LOS ANGELES — Trey Watkins scorched a walk-off double in the bottom of the 11th inning to lift the No. 2 seed LSU Tigers to a 11-10 victory over third-seeded UC Irvine in the opening round of the NCAA Los Angeles Regional Friday at Jackie Robinson Stadium.

After UC Irvine scored the go-ahead run in the top of the 11th on a suicide squeeze, the Tigers were down to their final out before Anteater reliever Eric Pettis walked Austin Nola, gave up a single to Alex Edward and walked Leon Landry to load the bases for Watkins, who pinch ran for Matt Gaudet in the 10th. With a 1-2 count, Watkins ripped a fastball over right fielder Sean Madigan’s head to score Nola and Edward, giving the Tigers the win.

With the win, the Tigers (41-20) improved to 23-1 all-time in NCAA Regional opening games. LSU will face top-seeded UCLA at 8 p.m. Saturday in Jackie Robinson Stadium. The Anteaters (37-20) will face No. 4 seed Kent State game at 4 p.m. Saturday.

LSU reliever Ben Alsup (5-0) earned the victory after pitching the final two innings and allowing one run on one hit. Tiger starter Austin Ross enjoyed another solid outing as the junior right-hander threw 6.1 innings, allowing five runs with no walk and five strikeouts. Pettis (9-4) was charged with the loss after allowing the double to Watkins.

Leading LSU offensively in the game was catcher Micah Gibbs, who finished 2-for-5 with a home run and five RBI. Landry and left fielder Mason Katz also contributed with three hits apiece.

“I’m so proud of our kids for making two comebacks with two out and nobody on in the ninth inning and again in the last inning,” said LSU coach Paul Mainieri. “It was a great effort, and we played the way that championship teams are supposed to play when they faced adversity. UC Irvine is such a difficult team to play; they’re relentless and they slap the ball all over the field. It’s a credit to the determination of our players that we were able to win this game.”

UC Irvine took a 2-0 lead in the second after designated hitter Drew Hillman was hit by a pitch and catcher Francis Larson followed two batters later with a two-run homer off Ross. The homer was Larson’s sixth of the season.

In the third, LSU cut the deficit to 2-1 when Mikie Mahtook lifted a deep sacrifice fly to left to score Matt Gaudet from third. Gaudet reached third after a single by Katz, who moved up to second on Mahtook’s sacrifice. The next batter, Gibbs singled to the left side to score Katz from second and tie the score at 2-2.

The Tigers took a 3-2 lead in the fourth when third baseman Alex Edward launched a solo homer to left off UC Irvine starter Daniel Bibona. Edward’s homer was his second of the season; his first was against Mississippi State on May 20.

The Anteaters tied the score at 3-3 in the fifth when left fielder Ryan Fisher hit a solo homer to right. The homer was Fisher’s fourth of the season. Ross had retired nine-straight batters before facing Fisher.

LSU broke the tie and went ahead 4-3 in the bottom of the frame when Tyler Hanover roped an RBI single through the right side to score Katz, who doubled to lead-off the inning. Mahtook, who also singled in the inning, advanced to third on Hanover’s single.

The next batter, Gibbs, blasted a three-run homer to center off Bibona to give LSU a 7-3 lead with no outs in the fifth. After Bibona retired Blake Dean with a groundout, UC Irvine brought in right-hander Evan Brock to pitch.

Ross left the game after forcing one out in the seventh. Senior right-hander Paul Bertuccini came on in relief of Ross with runners at the corners and one out. The first batter he faced, third baseman Brian Hernandez, singled up the middle to plate one run and cut the deficit to 7-4. First baseman Jeff Cusick followed with a bloop single to center to score another run making the score 7-5.

In the bottom of the seventh, the Tigers added another run when Gibbs lifted a sacrifice fly to center, scoring Mahtook and extending the LSU lead to 8-5.

UC Irvine responded in the eighth when Larson led off the inning with a solo homer to left, his second homer of the game, to make the score 8-6. Later in the inning, Casey Stephenson beat out an infield single off reliever Zach LaSuzzo and a run scored from third to pull UC Irvine within one at 8-7. LaSuzzo forced the next hitter, Hernandez, to ground into a 5-4-3 double play to escape the Anteater rally in the eighth.

In the top of the ninth, pinch hitter Jordan Leyland ripped an RBI double to tie the score and Ryan Fisher followed with a go-ahead RBI single to give UC Irvine a 9-8 lead heading into the bottom of the ninth inning.

After UC Irvine took a 9-8 lead heading into the bottom of the ninth, first baseman Blake Dean singled with two outs and Johnny Dishon came in to pinch run for Dean at first. The next batter, Austin Nola ripped a single to right in front of a diving Sean Madigan. The ball skipped past Madigan allowing Dishon to round third and beat Madigan’s throw to the plate, tying the score 9-9 and forcing extra innings.