Reigning Olympic field hockey champion Belgium beat New Zealand 2-1 on Sunday as the Red Lions took the lead in the Pool B standings after a twisting shot found the top corner of the goal, salvaging the win after a sluggish performance.

India and Australia are tied for second in the pool with three points each, with a chance to tie Belgium for the top spot in Pool B with games against Argentina and Ireland, respectively, on Monday.

"I think we didn't perform at our best level today, but I also think it's a bit normal at the Olympics. You're not going to perform every time at your best," said Florent van Aubel, who netted the game-winner shortly after New Zealand's equalizer. "We know we're a very good team, very good players. Everybody has an amazing skill level. Everything just has to come together."

New Zealand now has two losses to start the tournament, which puts them at the bottom of Pool B with three games to go. The top four teams in each pool will advance to the knockout rounds starting August 4.

The other afternoon matches began with an upset by the Spanish, who beat reigning World Cup champion Germany 2-0 to keep their chances alive after a blowout loss to Britain on Saturday left them reeling. The day concluded with a 4-0 blowout of host nation France by gold medal favorite Netherlands, as well as a 2-2 tie between South Africa and Great Britain — the first draw in either tournament.

The early women's matches of the day were closer on Sunday than on the opening day of the tournament. All but one game was decided by one goal, the exception being Germany's 2-0 triumph over Japan.

The Australian women's team beat South Africa 2-1, while Spain defeated Britain 2-1 in two tightly-contested matches.

The fourth-ranked Belgian women opened their tournament in the morning with a 2-1 effort against Pool A opponent China, punctuated by a top-net shot in the dying minutes of the game.

"I have always been a team player, but of course, it's always nice to score a goal in an opening game for this kind of tournament," scorer Charlotte Engelbert said.