North Korea didn't waste its chance.

The United States allowed a pair of goals while Wambach was off the field — one on a blunder by goalkeeper Hope Solo — then rallied for a 2-2 tie today in its opener at the Women's World Cup.

"When they scored right away as I went off I started to get worried," Wambach said. "So I started to run to the locker room to get stitches put in."

Former Kahuku High and University of Hawai'i player Natasha Kai entered the game for the U.S. in the 91st minute.

The top-ranked Americans, trying to regain the title they won in 1991 in China and 1999 at home, extended their unbeaten streak to 47 games. But playing in the toughest of four groups, they put pressure on themselves heading into games against third-ranked Sweden on Friday and Nigeria next Tuesday.

"I think the U.S. is the best in the world, but today they didn't perform to their maximum," North Korea coach said Kim Kwang-min, coach of the fifth-ranked North Koreans.

Wambach, playing on a sore right toe she injured against Finland Aug. 26, put the United States ahead in the 50th minute on a rainy night. She took a pass from captain Kristine Lilly on the right side of the penalty area and beat Jon Myong-hui with a 13-yard shot that the goalkeeper got her gloves on but failed to stop.

Five minutes later, Wambach was defending a cross when she collided with North Korea's Rik Kum Suk. Wambach fell to the ground, blood pouring from the back of her head onto her face and jersey.

U.S. coach Greg Ryan decided not to replace Wambach, who has 78 goals in 97 games with the national team.

"It was a very tough call," he said. "The doctors said they could get her back within just a few minutes. Abby is such an important player to this team. I though we could withstand playing 11 against 10."

In the 58th, Kil Son-hui hit a twisting, long strike that slipped through the Solo's hands, tying the score. Kim Yong-ae then pounced on a rebound in the 62nd and shot it past Solo, who didn't have a chance.

When the crowd screamed again, Wambach knew North Korea had taken a 2-1 lead.

"I really had to hurry up the process," she said. "I was yelling at the doctors to get it done quicker. I cursed some bad words,and hurried up and got my jersey on and ran as fast as I could."

Wambach re-entered the game two minutes later, and the United States tied it in the 69th when Heather O'Reilly scored her 12th goal — her first in the World Cup — taking a ball in the penalty area that couldn't be cleared and putting it into the roof of the goal.

"I was just moving around in the box and the ball just seriously wound up on my feet," O'Reilly said. "I just tried to get something on it — to get it on frame. It didn't feel like it came off my foot very cleanly. I was surprised it was as nice a goal as it was."

Solo made two saves in injury time to protect the lead, first sprawling to her right to parry away a shot, then grabbing a drive without allowing a rebound.

"For the fans and soccer it was great," Lilly said. "People saw attacking soccer, they saw goals, the teams were combatting to the very end."

In other games, Sweden tied Nigeria 1-1 in Group B and Japan tied England 2-2 in Group A.

Despite its usual poise, the U.S. looked unnerved at times before a crowd of 35,100 at Chengdu Sports Center Stadium in southwestern China.

North Korea, with many of the players that won last year's Under-20 Women's World Cup, pressed the Americans. The North Koreans ganged up at midfield to attack and mixed long balls with quick triangular passes.

"I would say I have never defended as much," U.S. defender Cat Whitehill said. "They came at us flying, they came at us with a ton of numbers. I'm just glad we were able to stop them enough to get a tie."

Ryan tried to encourage Solo, who rebounded from the bad first goal with some excellent late play.

"A hundred times Hope is going to save that one shot, but this is the one time it goes through her hand. It's unlucky," Ryan said.

Said Solo: "It's a day in the life of a goalkeeper. The conditions are slick and it is wet out there, but it happens."

In the other games:

— Victoria Svensson put Sweden ahead in the 50th minute at Chengdu, but Cynthia Uwak tied the score for Nigeria in the 82nd.