The defense was stifling, even suffocating at times.

The U.S. women put on a clinic Tuesday, forcing the Canadians to take bad shots or not allowing them to shoot at all.

The Americans, who cruised into the semifinals of the Olympic basketball tournament with a 91-48 rout, harassed Canada into three shotclock violations in the first 7 minutes.

''It's one thing to miss a shot, but to not be able to get a shot off says a lot about your defense,'' U.S. coach Geno Auriemma said. ''It's a double whammy. It brings your team closer together because it took all five guys to create that and takes the life out of the offense of the other team.''

The Americans cruised into the semifinals of the Olympic basketball tournament with a 91-48 rout of Canada.

While the four-time defending gold medalists seemingly couldn't miss in their previous game, a 114-66 rout of China, they were sloppy early on against Canada. So they turned to their defense.

''That's probably a better feeling than making a 3, when as a unit you found a way to stop them as a unit,'' said Diana Taurasi, who led the U.S. with 15 points. ''That's really hard to do because to get a shot off isn't the hardest thing, it might not be a quality one, but you can get a shot off.''

The Americans forced 26 turnovers and were off and running.

''We really were in sync defensively,'' Candace Parker said. ''Everyone knows that this team can score a lot of points, but we were locked in defensively and that will be huge going forward.''

The U.S. held Canada to the fewest points it has given up in an Olympic quarterfinals since beating Slovakia 58-43 in 2000.

''We get steals. We get deflections. We get rebounds, kick the ball out and here we go. We're rolling.'' said U.S. forward Tamika Catchings, who had four steals.