(CNN) -- U.S. coach Eddie O'Sullivan said he "couldn't be more proud" of his players after Thursday's hard-fought 13-6 victory over Russia at the Rugby World Cup in New Zealand.
It was the Eagles' first win of the tournament, after a 22-10 defeat to O'Sullivan's native Ireland on Sunday, with a superb 18th-minute try from scrumhalf Mike Petri after proving to be the difference between the two sides in wet conditions in New Plymouth.
The Russians, making their World Cup debut, took an early 3-0 lead through a penalty from flyhalf Yury Kushnarev , but the U.S. rallied despite several misses from goalkicker Chris Wyles and the Bears were left with just a solitary bonus point to show for their efforts.
"It was a great victory for us," former Ireland coach O'Sullivan told the World Cup's official website. "I thought it was a good match in these conditions. As a coach I couldn't have asked for more. I couldn't be more proud of these boys."
The Americans also beat Russia by a seven-point margin the last time they met, at the Churchill Cup in June, but U.S. captain Todd Clever said Nikolay Nerush's side were making impressive progress.
"I was very nervous at the end but they are a tough, tough team," the 28-year-old said. "They are improving every time we play them and are getting better and better."
Russia's team director Kingsley Jones was satisfied his players were able to run the U.S. close, but the 42-year-old former Wales flanker bemoaned the mistakes made by the team.
"Certain errors cost us the game," Jones said. "We didn't use our opportunities. Unfortunately, the lineouts didn't function but the team have come a long way to be competing right until the end of the game."
The U.S. now sit third in Pool C, level on points with Ireland in second but having played one game more.
O'Sullivan's team next play two-time world champions and current group leaders Australia on September 23, but face an uphill task to notch just a fourth victory in the four-yearly tournament's history. The other two were against Japan in 1987 and 2003.
Russia's next opponents are Italy, who lost their opener 32-6 to Australia on Tuesday, then the Wallabies and Ireland.