SAPPORO, Japan — The U.S. basketball team won its first three FIBA world championships games by an average of 20.3 points.

The Americans hadn't trailed after halftime, and took a double-digit lead into the final quarter of each game.

But after cruising past Slovenia 114-95 on Tuesday night, the Americans said they still haven't peaked.

It's probably a good thing, too, because the competition promises to improve when the tournament moves to the knockout stage this weekend. The victory over Slovenia guaranteed the U.S. a berth in the second round.

"We just want to fine-tune all parts of our game," captain Dwyane Wade said. "Offensively, we want to be a little more crisp. We want to continue to have a killer mentality. We were on the verge of beating this team by 30 or 40, but we kind of let them back in the game."

The U.S. led by as many as 29 points before the Slovenians pulled to within 11 in the final minutes. The outcome was never in doubt, but Slovenia's rally exposed holes in the American defense.

The U.S., which has forced 64 turnovers in three games, has played superb defense at times. But it hasn't maintained a high level through 40 minutes.

In the opener, the U.S. allowed Puerto Rico to shoot 54 percent from the floor. On Tuesday night, the Americans limited Slovenia to two 3-pointers in the first half, but later gave up several wide-open looks.

"Sometimes there's slippage, and that's something we're trying to work on and trying to get better," assistant coach Jim Boeheim said. "We're giving up (95 points per game), but we're playing good defense. Because we're scoring so much, teams are going to score points, too. We're actually playing, in stretches, really good defense."

Against Slovenia, the U.S. made a big leap in another area: long-range shooting. The Americans made 50 percent (10-of-20) from beyond the 3-point arc against Slovenia after shooting 33 percent against Puerto Rico and 30 percent against China.

"We haven't shot the ball the way we know we can, so that's a positive for us," Wade said. "Once they're falling, our strength, of course, is penetrating and also pressuring the ball. Once our 3s are falling, we're a pretty good team. We're a darned good team."

Still, Wade said he thought the U.S. took a small step backward from its second game, a 121-90 rout of China and Yao Ming on Sunday night.

"I think today we played in waves," said Wade, who leads the Americans with 19.7 points per game. "I think when we were playing good defensively today, we looked great. But we also looked average. This is only our third real game, besides exhibitions, together. We've still got games to get better."