A goal, a promise, and soon, she hopes, a World Cup title.

The United States women had fans on edge once again until Wambach broke a tense tie with her header off a corner kick in the 79th minute yesterday. Alex Morgan scored three minutes later to seal a 3-1 semifinal victory over France.

Next up, a trip to the World Cup final Sunday in Frankfurt that will be the first for Americans since 1999, when they last won it all. They’ll play Japan, which upset Sweden, 3-1, to move one step away from realizing its own dream.

“We’ve achieved part of our goal. We’re in the final,’’ Wambach said. “We want to complete it. We want to be world champs.’’

France was the surprise of the tournament, making the semifinals with a creativity and flair that was breathtaking to behold. And for much of the game, the US couldn’t contain Les Bleues.

“We didn’t play well today,’’ US coach Pia Sundhage said. “However, we find a way to win and that’s a credit to the players’ hearts. That’s what makes it so wonderful to be coach of this team.’’

With the US struggling to create opportunities in the middle, Sundhage replaced Carli Lloyd with sparkplug Megan Rapinoe early in the second half, moved Lauren Cheney inside, and pulled Wambach back to the midfield.

The difference was noticeable immediately. The Americans were able to push forward and began threatening French goalkeeper Berangere Sapowicz.

Finally, in the 79th, the Americans won a corner kick.

“I told [Cheney] at halftime, ‘Put the ball to the back post, and we’re going to get a goal,’ ’’ Wambach said.

Cheney delivered the ball perfectly to the far post and, just as Wambach had predicted, she soared over the scrum and pushed the ball past Sapowicz.

“I knew Abby was going to beat her,’’ Cheney said, referring to the French defender who practically mugged Wambach to try and contain her.

Asked how, Cheney said, “Because she’s Abby Wambach.’’

Wambach let out a scream and did a sliding sprint into the corner, where she was mobbed by her teammates. It was her third goal of the tournament and 12th of her career, tying fellow American Michelle Akers for third on the all-time World Cup scoring list.

Morgan then put the game out of reach, outracing four defenders and then stutter-stepping in front of the goal, throwing Sapowicz off, and leaving the American with a wide-open shot.

“The priority is not to accept another goal,’’ France coach Bruno Bini said through a translator. “When that happens, you’ve had it. We conceded another goal and that was it for us.’’

Despite the loss, the World Cup was a resounding success for the French. In just their second World Cup appearance, they reached the semifinals and qualified for next summer’s London Olympics.

“Do you know any coach who will tell you it’s fantastic to lose?’’ Bini asked. “But we must give credit where credit is due.’’

The US was staked to an early lead by Cheney’s goal in the ninth minute. But with Louisa Necib calling the shots, France dominated for most of the game, finishing with a 25-11 advantage in shots. The French missed two great chances in the first half, with goalkeeper Hope Solo having to tip a Gaetane Thiney shot away in the 30th and Sonia Bompastor rattling the crossbar two minutes later.

Finally, in the 55th, France got its equalizer. Bompastor floated in a cross from about 30 yards and, with Thiney right in front of her, Solo had little opportunity to move. The ball flew right past her.

But part of the blame goes to Becky Sauerbrunn, who was starting in place of the suspended Rachel Buehler.

“I think [Thiney] got a step ahead of her,’’ Solo said. “But I definitely expect our defenders, when the ball goes in the box, to get it out of there.’’

But just as they did against Brazil, the Americans got stronger and stronger as the game went on before Wambach - who scored a critical goal in the waning moments against the Brazilians - came through.

“In the end, we’re in the finals,’’ Wambach said, “and that’s all that matters.’’