U.S. women still perfect

Abby Wambach's goal gave the U.S. its first 3-0-0 mark in Olympic group play. Stanley Chou/Getty Images

The U.S. women's national team didn't deliver a perfect performance against North Korea, but the 1-0 victory was enough for a third win in three games -- the first perfect run for the U.S. in an Olympics group stage -- and top spot in Group G.

Abby Wambach scored the game's only goal in the 25th minute -- following a slick pass from Alex Morgan -- and with the U.S. dominating possession for almost the entirety of the match, its defense was left to defend just a few half-chances.

That said, the U.S. attack, especially in midfield, didn't look as fluid as it did in defeating France and Colombia. More passes missed their intended target against North Korea, which it must be said employed a kind of tenacious defending that at times strayed over the edge. Substitute Choe Mi Gyong was sent off in the 81st minute following a second yellow card for a late challenge on Lauren Cheney, but there were several other challenges that appeared to be yellow-card worthy.

But overall, the U.S. did what it needed to do on the day and will now wait to see whom it will face in the quarterfinals.

U.S. manager Pia Sundhage named an unchanged lineup from the side that beat Colombia 3-0, though this still counted as something of a surprise with Tobin Heath remaining on the bench at the expense of Heather O'Reilly. North Korean counterpart Sin Ui Gun made three alterations from the team that was hammered by France 5-0: O Chang Ran replaced Jo Yun Mi in goal, Pong Son Hwa slid into the center of defense and Kim Chung Sim resumed her role on the right side of midfield that saw her score twice in the team's 2-0 win over Colombia.

The match started with North Korea clogging the midfield and continually going to ground in a bid to put the U.S. off its game, yet the tactic didn't prevent the Americans from owning the ball. Morgan's fifth-minute effort was touched around the post by O Chang Ran after a layoff from Carli Lloyd. The U.S. striker went close again 10 minutes later after finishing off a series of passes with Wambach but succeeded only in hitting the post.

Further upfield, North Korea was doing its best to limit the influence of Cheney via a string of rough challenges. One incident in the 16th minute resulted in Cheney being booked for retaliation after a tackle from Kim Song Hui.

But no matter how physical things got in midfield, Cheney managed to shake loose of North Korea's attentions long enough to set up the U.S. goal in the 25th minute. The U.S. midfielder clipped a ball over the North Korea defense to Morgan, who showed good patience before slipping a ball through to Wambach who scored easily from 7 yards.

The U.S. continued to dominate the match and created a slew of set piece opportunities as a result. Yet the team's best chances came from the run of play. In the 39th minute, Wambach's redirection from Lloyd's deflected drive hit the post. Lloyd should have done better with another chance two minutes later but ballooned her shot over the bar after outstanding work out on the flank by O'Reilly.

Heath was brought on for Megan Rapinoe at halftime and wasted no time in getting involved. A slick buildup that started with O'Reilly's ball-winning tackle ended with Morgan setting up Heath for a clear shot, but her chip sailed harmlessly over the bar.

From there, the game somewhat petered out as the Americans opted to attack more down the middle, battling the heart of the North Korea defense. The quality of the U.S. passing began to erode, as well, allowing North Korea some opportunities to counterattack. Not that it mattered; the American back line managed to deal with the half chances and with a second goal proving hard to come by, Wambach & Co. set about trying to re-establish their attacking rhythm.

North Korea was reduced to 10 players when substitute Choe was booked twice for late challenges in a four-minute span but even that couldn't inspire outward change in the flow of the game. While the U.S. started stringing more passes together it couldn't stop itself from trying to grab a second goal, making the last few minutes a little tenser than they needed to be. Choe Un-Jun had one shot from just outside the box that sailed over the bar; it proved to be the closest North Korea would come to grabbing an equalizer.

As the U.S. looks ahead to the quarterfinal, the squad can largely breathe easy. After some shaky moments against France the defense has tightened up considerably, although its tendency to drop too deep when opponents run at it remains a cause for concern. In attack, however, the U.S. is still waiting for Cheney to reach the form that drew rave reviews at last summer's World Cup. Perhaps Cheney is still too worried about her defensive responsibilities, something Sundhage suggested as a possible issue prior to the tournament.

The good news is that the knockout stages should see the U.S. matched up against teams who will bunker in a bit less than North Korea did. If New Zealand wins its game against Cameroon, the U.S. will go up against the Ferns; otherwise, it will face northern neighbor Canada. Either side should yield the kind of open spaces in which Cheney thrives.

But as long as the U.S. has Wambach and Morgan up top, the Americans should be able to find enough goals to secure a victory, even on days when they're a few notches short of perfect.

Player ratings: (1-10; 10 = best)

G: Hope Solo, 6 -- Could have set up a lawn chair in her area and still done the job. Also could have come off her line one time late on to snuff out a North Korea attack, but was safe with her handling on the rare occasions when she touched the ball.

D: Kelley O'Hara, 7 -- Her best game of the tournament especially in terms of her one-on-one defending. Also a threat going forward.

D: Rachel Buehler, 7 -- Solid on all fronts, tough in the tackle and kept it simple with her passing.

D: Christie Rampone, 6.5 -- Used her speed to good effect and while she had the occasional wayward pass, she organized the back line well.

D: Amy LePeilbet, 6 -- Her passing was a bit ragged at times but no complaints about her defending, especially when isolated against North Korea attackers. Overall, she's looking much more composed than at the World Cup.

M: Megan Rapinoe, 4 -- Was dangerous with her set piece deliveries but tried to force her passes too much from the run of play. Taken off at halftime.

M: Carli Lloyd, 6 -- Wasn't quite as effective as in games past and faded a bit as the game went on. Yet helped out defensively and chose her moments to get into the attack well. Should have done better with a late first-half chance, however.

M: Lauren Cheney, 5 -- Still looks short of her best although she took a ton of abuse from the North Korea midfield. Her deft chip set up the Americans' opener but overall she struggled to connect in the attacking third.

M: Heather O'Reilly, 7 -- Tracked back well on defense and had some good moments in the attack. On another day she might have had two assists.

F: Abby Wambach, 7 -- Took her goal with aplomb and linked up well with Morgan. Unlucky not to get a second.

F: Alex Morgan, 6.5 -- Was much sharper with her passing than against Colombia and showed good composure in setting up the U.S. goal.


M: Tobin Heath, 5.5 -- Tucked inside to good effect but needed to hit the target with a clear opportunity early in the second half. Looked less effective after taking Cheney's place in the center of midfield.

D: Becky Sauerbrunn, 6.5 -- Had a key clearance late and overall showed her usual high level of composure.

M: Amy Rodriguez, 5 -- Was busy after coming on for Cheney but showed little end product from her attempts to dribble at the North Korea defense.

Jeff Carlisle covers MLS and the U.S. national team for ESPN.com. He is also the author of "Soccer's Most Wanted II: The Top 10 Book of More Glorious Goals, Superb Saves and Fantastic Free-Kicks." He can be reached at eljefe1@yahoo.com.