CARSON >> Just when it appeared that the game was slipping away from the Galaxy, Giovani dos Santos and Gyasi Zardes entered as second-half substitutes to try and save the night.

That’s exactly what they did in Wednesday’s U.S. Open Cup quarterfinal against Seattle.

The duo replaced Alan Gordon and Mike Magee in the 74th minute.

In the 77th minute, dos Santos intercepted an errant pass from Seattle defender Zach Scott to tie the score and eight minutes, Zardes helped set up Sebastian Lletget for the eventual winning goal, leading the Galaxy to a 4-2 victory in front of 3,409 in the StubHub Center track stadium to advance to the semifinals for the first time since 2006.

“Really, it was all coaching,” Galaxy coach Bruce Arena joked. “You roll the dice sometimes. The other part you always have to think about there is that we might be playing 120 minutes, so you have to be careful, but obviously, we injected those players in the game to get a goal.

“Sebastian (Lletget) hasn’t had a regular shift in a while and this was good for him and he did a good job.”

Lletget closed out the scoring the three minutes later another goal.

The Galaxy will face FC Dallas in the semifinals, Aug. 10. The site will be announced today.

“I knew they were going to bring a lot of energy,” Lletget said of dos Santos and Zardes. “They made such a big impact right away. (Alan Gordon) Gordo and (Mike) Magee did a great job, but you know you get tired and they just brought energy, they’re smart players and just being clever, Gio (Giovani dos Santos) getting the goal, anticipating the play and he did well to finish it and Gyasi (Zardes) giving me the perfect ball.

“I’m going to enjoy every minute that I get.”

Seattle had taken a 2-1 lead in the 58th minute on Herculez Gomez’s goal in the 58th minute.

The Galaxy was able to send the game into halftime tied 1-1 thanks to Alan Gordon redirecting a shot from Baggio Husidic into the net in the 17th minute.

Seattle opened the scoring in the fourth minute when Michael Farfan took advantage of a mistake by Leonardo, stripping the ball and then scoring by Galaxy goalkeeper Clement Diop. It was an eventful first half for Leonardo, who also received a yellow card in the 31st minute.

Arena said he sent dos Santos and Zardes into the game to get one goal and he ended up with three and a berth in the semifinals.

“Anyone that thinks that we haven’t tried to do this … we haven’t been able to do, but it is not because it wasn’t important,” Arena said of advancing. “It (the Open Cup) is important and the next game will be a tough game and we will be ready to go.”

The teams will meet again in MLS play, July 31 in Seattle.