ISTANBUL (AP) — The United States survived its first tough test at the world championships, edging Brazil 70-68 on Monday when Leandro Barbosa's shot rattled out at the buzzer.

Kevin Durant scored 27 points and Chauncey Billups added 15 for the Americans (3-0), who essentially clinched Group B with the victory.

But this was further proof that a world title won’t come easily for this young US team – if it comes at all.

After the Americans trailed most of the first two quarters, Lamar Odom’s dunk with 7:14 left put them ahead 64-62. But they couldn’t build on the lead during a tense final few minutes, and Brazil had two chances to send the game to overtime.

Following a miss by Billups, Brazil got the ball and Marcelo Huertas was fouled on a drive to the basket with 3.5 seconds remaining.

He missed the first free throw and then the second intentionally, tracking it down in the corner and firing it underneath to Barbosa, who put up a shot over Kevin Love, only to have it bounce off the back and front of the rim.

Barbosa finished with 14 points after a strong start for Brazil (2-1). Marcus Vinicius scored 16, and Tiago Splitter had 13 while battling foul trouble in the second half.

Also in Group B, Iran (1-2) earned its first victory ever at the world championship by beating Tunisia (0-3) behind 23 points and 13 rebounds from Hamed Haddadi of the Memphis Grizzlies.

Uros Slokar and Jaka Lakovic scored 15 points each, and Slovenia (2-1) beat Croatia 91-84 in the first game of the day in Istanbul.

With NBA big men Nene, Anderson Varejao and Splitter, Brazil was considered one of the teams with enough size to topple the undersized Americans.