Croatia used a late surge Sunday to pull away for a 8-6 win over Greece in the opening match of the men's water polo competition at the London Olympics.
With the score level at 5-5 after three quarters, Croatia netted three unanswered goals from Niksa Dobud, Miho Boskovic and Sandro Sukno to take control of the match.
"It was a bit nervous start for us, the first two quarters, and after we started to play more aggressively our quality came to give us the result," Boskovic said.
The win puts Croatia, one of the leading medal contenders in a crowded field in London, atop Group A.
Spain also opened its Olympic campaign in Group A with an easy 14-6 victory over Kazakhstan behind five goals from Filipe Perrone Rocha.
"It was amazing, we feel like we were flying in the water," Rocha said. "To score five goals is perfect, but the most important thing is that we were playing amazing and that we beat Kazakhstan."
In the group's third match later Sunday, 2011 world champion Italy takes on Australia.
The 12-team field is broken down into two groups of six for the preliminary stage, and the top four teams from each group advance to the knockout round.
The marquee matchup on day one of the competition is later Sunday in Group B between three-time defending champion Hungary and gold medal-favorite Serbia.
Hungary, which is looking to win an unprecedented fourth consecutive gold, hasn't lost an Olympic match in 12 years, a streak of 17 games that dates back to the Sydney Games. Serbia, meanwhile, has been the most impressive team in the past few years, and has its sights set on the nation's first water polo gold as an independent nation.
Two other serious medal contenders also face off in the final game of the day between the United States and Montenegro. The U.S. is looking to improve upon its second-place finish in Beijing four years ago and win the Americans' first water polo gold since 1904.
In the other Group B match, Romania plays host Great Britain.