Landon Donovan and Robbie Keane sent David Beckham off a winner in his final MLS game as Los Angeles won its second consecutive MLS Cup with a 3-1 victory over Houston at the Home Depot Center.

Donovan and Keane scored second half penalties to complete the Galaxy comeback and ensure Beckham left the Galaxy on a winning note. Houston forward Calen Carr scored the opener shortly before halftime, but Omar Gonzalez equalized with a header in the 61st minute before Donovan scored the decisive penalty four minutes later.

Keane's spot kick in second half stoppage time allowed Beckham to trot off moments before the final whistle to thunderous applause as the Galaxy fulfilled its expectations and secured yet another title.

"It's a little surreal, to be honest," Donovan said. "I think, in any sport, to repeat, it's really hard to do. The playoff was run was great, but what got us here was the turnaround in July. We have to give ourselves a lot of credit about how we did when we were down. That's the sign of a champion. We showed that again today, too."

Donovan should have put the Galaxy in front inside the opening quarter of an hour after all three Designated Players combined to carve open the Dynamo. Beckham hit a sumptuous diagonal ball to start the counter toward Keane down the left side. Keane squared for Donovan, but Donovan somehow slotted wide from eight yards.

The early miss marked the transition from a bright Dynamo start to a relatively even exchange between the sides. Most of the half chances fell to the Galaxy as the game stretched out through midfield, but Kofi Sarkodie forced a sharp angle save from Josh Saunders after 26 minutes to foreshadow the opening goal shortly before halftime.

Carr's opener stemmed from a flat Galaxy defensive line and a clever run into space. Adam Moffat played over the top right into space as Carr raced past Tommy Meyer. Carr maintained his composure and slotted home from a sharp angle to open the scoring a minute before halftime.

Los Angeles responded after the interval and seized control of the affair. Keane saw an effort correctly ruled out three minutes after the break and struck a near post effort turned away by Tally Hall at the near post five minutes later.

"Sometimes, the momentum swings come in increments and they put pressure on your team," Houston coach Dominic Kinnear said. "You knew they were going to come out and push. We all knew that going into the game.

"You know they're going to have their moments during the game, which they did. So did we. You just hope during those moments when they're on top of you that you withstand the pressure and you don't get scored on."

The equalizer finally arrived in the 61st minute after a period of sustained Galaxy pressure. Juninho clipped a diagonal ball from the right wing toward the back post. Gonzalez climbed highest at the back post and directed his header into the far side netting to send the Home Depot Center crowd into delirium.

Gonzalez played a critical role to prompt the winner four minutes later as the Galaxy exposed the Dynamo's surprising frailty on crosses and set pieces. He climbed highest once again to nod the ball down and the scrum eventually forced Ricardo Clark to handle and referee Siliviu Petrescu to point to the spot.

Donovan assumed the spot kick duties and crouched for a moment to steady himself. He dispatched the penalty into the lower right side of the net as Hall dove the other way to notch his fifth MLS Cup goal and spark wild celebrations among the Galaxy faithful.

Houston threw Brian Ching into the mix in the waning stages in a desperate search for an equalizer, but Keane settled matters by winning and converting a spot kick in second-half stoppage time to ensure the perfect Hollywood ending unfolded as planned.

"It was our goal at the start of the season," said Beckham. "I spoke about it before, we always want to win a championship at the end of the year.

"It's very special," added Beckham. "Today's a good day."