The US "Dream Team" saw off a spirited display by Greece to seal a 77-71 win in the men's basketball competition.
The Americans, humbled by Puerto Rico on Sunday, showed more fight against the hosts in front of a hostile crowd.
But they did not have things all their own way as the Greek players drained a succession of three-pointers to keep the contest close in the second half.
USA captain Tim Duncan fouled out, but Lamar Odom and NBA rookie LeBron James rose to the challenge with key baskets.
US coach Larry Brown said his team had upped their level of performance since losing to Puerto Rico, but said there was more to come.
"We had a chance to bury them, We're trying to entertain rather than just play. We have to do away with that or we're going to be in serious trouble," he said.
Greek coach Panagiotis Giannakis praised his team's fighting qualities.
"We didn't go on to the court with fear. My boys had the courage to keep coming back until the end," he said.
Allen Iverson scored 17 points despite having a fractured right thumb, while Duncan had 14.
Antonios Fotsis top scored for Greece with 22 points.
In other action, China bounced back from a disappointing loss to Spain by beating New Zealand 69-62.
Houston Rockets centre Yao Ming led the Chinese team, finishing with 39 points and 13 rebounds.
Australia easily beat Angola 83-59, while Lithuania claimed a 98-90 win over Puerto Rico.
NBA center Pau Gasol scored 26 points and Spain managed 15 points in a row in the fourth quarter to beat Argentina 87-76.
And Milos Vujanic hit a pair of free throws with 5.6 seconds to play to give world champions Serbia and Montenegro their first win of the tournament, a 74-72 triumph over Italy.