Each day of the Tokyo Games, NBC Olympics will provide a roundup of news from a variety of sports. Catch up here on all the storylines and must-see highlights you may have missed while you were sleeping. You can also get a jump on the next day/night's viewing with the Day 4 preview.

The first and probably closest duel between Katie Ledecky and Australia's Ariarne Titmus lived up to the hype Monday in Tokyo.

Ledecky is more likely to win the longer races, especially in the new Olympic discipline of the 1500m freestyle. Titmus should have the edge at 200 meters. The 400m race is where the stars' strengths overlap, and no swimmer in history has been close to the times the two rivals have posted.

The American held a narrow lead until the last turn, when Titmus nosed ahead and dethroned the Olympic champion. Her time: 3:56.69, a result bested only by, of course, Katie Ledecky in Rio.

Ledecky congratulated her new rival, with both swimmers admiringly talking about the way they've pushed each other. Meanwhile, an Australian coach was a little excited.

In another close one, first-time Olympian Torri Huske missed a medal by 0.01 seconds in the 100m butterfly. The 18-year-old finished 0.14 seconds behind the winner, Canada's Margaret MacNeil. 

The U.S. rebounded with an emphatic win in the men's 4x100-meter freestyle relay. Caeleb Dressel took his first of what could be a Phelpsian, Ledeckyian or Spitzian medal haul, but it was Zach Apple who stamped his authority on the race with a 46.69-second anchor leg.

In other sports, the theme from the film Top Secret, called Skeet Surfing, summed up the day for U.S. athletes quite well, with U.S. shooters winning gold in the men's and women's skeet events while surfers continued to impress in the new Olympic sport. 

The evening action saw many firsts and seconds: the first-ever gold medal for the Philippines in any sport, the first non-Chinese athletes to win a table tennis gold since 2004, the first Canadian woman to win a judo medal, Kosovo's second gold medal of the Olympics and third ever, Jordan's second medal ever, and Hong Kong's second-ever gold medal. 

Speaking of action on the water, U.S. athletes have seemed right at home in the waves as surfing makes its Olympic debut.

U.S. teen Caroline Marks posted a stellar score of 15.33 (8.00 and 7.33), the best score of the day in both men's and women's competion, to defeat Japan’s Mahina Maeda and advance to the quarterfinals against Costa Rica’s Brisa Hennessy. Fellow American Carissa Moore managed a 5.77 late in her heat against Peru’s Sofia Mulanovich to take a close 10.34-9.90 win.

The shocker in the women’s event was the loss by Australia’s Stephanie Gilmore, like Moore one of the dominant surfers of the past decade, to South Africa’s Bianca Buitendag.

Kolohe Andino advanced in the men's competition at the expense of fellow U.S. representative John John Florence. Andino had the best score (14.83) in the men's event until Australian Owen Wright won the day's last pairing with a 15.00.

The surfing medal bouts have been moved ahead from Wednesday to Tuesday due to changes in the weather. Tropical Storm Nepartuk, weakening and downgraded from typhoon status, has already forced some rescheduling in archery and rowing. The waves ahead of the storm have been strong enough to let the surfers show their stuff.

The ROC dethroned defending champion Japan in the men's team competition by the slimmest of margins — 262.500 to 262.397. China wasn't far behind at 261.894.

U.S. gymnasts had a strong start and held fourth place after five rotations but wound up in fifth place for the third consecutive Olympics, passed at the end by Great Britain.

Next up: Simone Biles and the U.S. team try to shake off an erratic qualification performance to win the team gold Tuesday evening in Tokyo.

FULL RESULTS

U.S. shooters Vincent Hancock and Amber English took twin gold medals in the men's and women's skeet competitions. For Hancock, it was his third gold medal in four Olympic appearances. English won in her Olympic debut.

The sentimental favorite of the day was 57-year-old Kuwaiti Abdullah Al-Rashidi, a seven-time Olympian who took his second straight Olympic bronze in the men's event. But Hancock missed just one of his 60 shots, leaving little room for anyone to keep him from gold.

English missed four times and hung in long enough for defending champion Diana Bacosi of Italy to have a few costly misses. World record-holder Wei Meng of China, who hit 124 of 125 targets in qualifying, took bronze.

Fencing: Mariel Zagunis, the 2004 and 2008 gold medalist, reached the quarterfinals before finishing out of the medals. Dagmara Wozniak, competing in her fourth Olympics, lost her first bout, as did Anne-Elizabeth Stone, who has finished third and fifth in the last two world championships but was making her Olympic debut. The U.S. men's foil fencers were upset, with first seed Gerek Meinhardt and third seed Alex Massialas ousted in the Round of 32, leaving Nick Itkin as the only American to get to the Round of 16. But the big winners were Argentina’s María Belén Pérez Maurice and her coach, Lucas Guillermo Saucedo, as Saucedo proposed during her interview after she lost her opening bout in sabre.

Skateboarding: The combined ages of the three women's street medalists is 42. Japanese skaters Momiji Nishiya (13) and Funa Nakayama (16) took gold and bronze, while Rayssa Beal (13) of Brazil took silver.

Rugby: The U.S. men pulled out two dramatic victories in pool play to clinch a spot in the quarterfinals.

Taekwondo: 2012 bronze medalist Paige McPherson won her first two bouts before losing in the semifinals and lost her fight for bronze.

Softball: Another day, another walk-off for the U.S. women, this time to cap a rally from 1-0 down to beat Japan 2-1. The game was statistically meaningless because both teams have advanced to the gold medal game, but will the win mean anything from a psychological point of view?

Judo: More gold for two countries with vastly different expectations - Japan and Kosovo.

Archery: The U.S. men's team bowed out in the quarterfinals.

Basketball: Neither U.S. team was in action, but Dallas Mavericks star Luka Doncic celebrated Slovenia's Olympic debut with 48 points in a 118-100 win over Argentina. 

Tennis: In a peculiar quirk of the draw, no U.S. players were in action. Top men's seed Novak Djokovic took another easy win, as did Naomi Osaka. (Brackets: men's singles, women's singles)

Table tennis: It’s not a sudden rush to the podium, but the U.S. women are on a roll, with two players in the Round of 32. Liu Juan beat 31st-seeded Slovakian Barbora Balazova in straight sets and has only dropped two of 14 sets in her three matches. Three-time Olympian Lily Zhang, who had a bye to the Round of 64, defeated Nigeria’s Offiong Edem. (Bracket)

Beach volleyball: Kelly Claes and Sarah Sponcil, the youngest duo to compete for the U.S. in the sandy sport, simply crushed it on the last several points to rally past Latvia for a win.

MEDALISTS

Archery (men’s team): Gold - South Korea, Silver - Chinese Taipei, Bronze - Japan

Canoe/kayak (men’s canoe slalom): Gold - Benjamin Savsek (SLO), Silver - Lukas Rohan (CZE), Bronze - Sideris Tasiadis (GER)

Cycling (men’s mountain bike): Gold - Thomas Pidcock (GBR), Silver - Mathias Flueckinger (SUI), Bronze - David Valero (ESP)

Diving (men’s synchronized platform): Gold - Daley/Lee (GBR), Cao/Chen (CHN), Bondar/Minibayev (ROC)

Fencing (women’s sabre): Gold - Sofia Pozdnyakova (ROC), Silver - Sofya Velikaya (ROC), Bronze - Manon Brunet (FRA) 

Fencing (men’s foil): Gold - Cheung Ka Long (HKG), Silver - Daniele Garozzo (ITA), Bronze -  Alexander Choupenitch (CZE)

Judo (women’s 57kg): Gold - Nora Gjakova (KOS), Silver - Sarah Leonie Cysique (FRA), Bronze - Yoshida Tsukasa (JPN), Bronze - Jessica Klimkait (CAN)

Judo (men’s 73kg): Gold - Shohei Ono (JPN), Silver - Lasha Shavdatuashvili (GEO), Bronze - An Chang-Rim (KOR), Bronze - Tsogtbaatar Tsend-Ochir (MGL)

Shooting (women’s skeet): Gold - Amber English (USA), Silver - Diana Bacosi (ITA), Bronze - Wei Meng (CHN)

Shooting (men’s skeet): Gold - Vincent Hancock (USA), Silver - Jesper Hansen (DEN), Bronze - Abdullah Al-Rashidi (KUW) 

Skateboarding (women’s street): Gold - Nishiya Momiji (JPN), Silver - Rayssa Leal (BRA), Bronze - Nakayama Funa (JPN)

Swimming (women’s 100m butterfly): Gold - Margaret Macneil (CAN), Silver - Zhang Yufei (CHN), Bronze - Emma McKeon (AUS)

Swimming (men’s 100m breaststroke): Gold - Adam Peaty (GBR), Silver - Arno Kamminga (NED), Bronze - Nicolo Martinenghi (ITA) 

Swimming (women’s 100m freestyle): Gold - Ariarne Titmus (AUS), Silver - Katie Ledecky (USA), Bronze - Li Bingjie (CHN)

Swimming (men’s 4x100m freestyle): Gold - United States, Silver - Italy, Bronze - Australia

Table tennis (mixed doubles): Gold - Mizutani/Ito (JPN), Silver - Xu/Liu (CHN), Bronze - Lin/Cheng (TPE)

Taekwondo (women’s 67kg): Gold - Matea Jelic (CRO), Silver - Lauren Williams (GBR), Bronze - Hedaya Malak (EGY), Bronze - Ruth Gbagbi (CIV) 

Taekwondo (men’s 80kg): Gold - Maksim Khramtsov (ROC), Silver - Saleh Elsharabaty (JOR), Bronze - Seif Eissa (EGY), Bronze - Toni Kanaet (CRO) 

Triathlon (men’s race): Gold - Kristian Blummenfelt (NOR), Silver - Alex Yee (GBR), Bronze - Hayden Wilde (NZL)

Weightlifting (women’s 55kg): Gold - Hidilyn Diaz (PHI), Silver - Liao Qiuyun (CHN), Bronze - Zulfiya Chinshanlo (KAZ)

TEAM EVENTS

3x3 basketball (women): China def. Japan 15-12, Romania def. Mongolia 22-14, ROC def. Romania 21-12, Japan def. Italy 22-10, France def. Mongolia 22-18, United States def. Italy 17-13, United States def. China 21-19, France def. ROC 17-14 

3x3 basketball (men): China def. Belgium 21-20, Serbia def. Japan 21-11, ROC def. Japan 19-16, Serbia def. Latvia 22-16, Belgium def. Netherlands 18-17, China def. Poland 21-19, ROC def. Latvia 19-15, Netherlands def. Poland 22-20 

Basketball (women): Spain def. South Korea 73-69, Serbia def. Canada 72-68

Basketball (men): Slovenia def. Argentina 118-100, Spain def. Japan 88-77

Handball (men): France def. Brazil 34-29, Germany def. Argentina 33-25, Denmark def. Egypt 32-27, Spain def. Norway 28-27, Portugal def. Bahrain 26-25, Sweden def. Japan 28-26

Field hockey (men): Belgium def. Germany 3-1, Great Britain def. Canada 3-1

Field hockey (women): Netherlands def. Ireland 4-0, Australia def. China 6-0, Great Britain def. South Africa 4-1, New Zealand def. Japan 2-1, Argentina def. Spain 3-0, Germany def. India 2-0

Rugby (men): Fiji def. Japan 24-19, Great Britain def. Canada 24-0, New Zealand def. South Korea 50-5, Argentina def. Australia 29-19, South Africa def. Ireland 33-14, United States def. Kenya 19-14, Great Britain def. Japan 34-0, Fiji def. Canada 28-14, New Zealand def. Argentina 35-14, Australia def. South Korea 42-5, United States def. Ireland 19-17, South Africa def. Kenya 14-7

Softball: United States def. Japan 2-1, Canada def. Italy 8-1, Mexico def. Australia 4-1

Volleyball (men): Iran def. Venezuela 3-0, ROC def. United States 3-1, Poland def. Italy 3-0, France def. Tunisia 3-0, Japan def. Canada 3-1, Brazil def. Argentina

Water polo (women): United States def. China 12-7, ROC tied Hungary 10-10, Australia def. Netherlands 15-12, Spain def. Canada 14-10