BATON ROUGE (AP) — Austin Ross tied a career high with 10 strikeouts, and LSU scored seven two-out runs in the seventh inning for a 10-2 victory over Southern in Friday’s opening game of the Baton Rouge NCAA regional.

Ross gave up a two-run homer to Victor Franklin in the first inning but lasted until there were two outs in the top of the seventh, when reliever Paul Bertuccini struck out Franklin with two runners on base and Southern leading 2-1.

‘‘Ross kept us in the game,’’ LSU coach Paul Mainieri said. ‘‘They scored two runs in the first three pitches, and then he absolutely pitched fantastic the rest of the way, which is not an easy thing to do for a pitcher when he gives up runs early to regroup and hold them down.’’

Southern starter Chase Richard (6-4) took the loss but did not allow an earned run until the seventh, when Austin Nola’s two-out single drove in pinch runner Chris McGhee to tie the score at 2.

Suddenly, the Jaguars (30-16) began falling apart, and any realistic hope of upsetting LSU (47-16) faded fast.

Nola, who took second on the throw to the plate, scored the go-ahead run on DJ LeMahieu’s single to center off of reliever Kyle Wahl. LeMahieu took second when center fielder Toddrick Stevenson mishandled the ball, then scored on Ryan Schimpf’s single to center.

Blake Dean, who’d gone hitless against Richard, singled on a soft-liner to left-center. Schimpf challenged left fielder Romey Bracey’s arm and narrowly beat the throw to third while Dean took second. Then Southern first baseman Frazier Hall booted Micah Gibbs’ hard grounder, allowing Schimpf and Dean to score.

Mikie Mathook was given first base when Wahl’s pitch appeared to graze his sleeve, then pinch hitter Derek Helenihi capped the rally by belting a two-run double to the left field wall to make it 8-2 before he was thrown out trying for a triple.

After the LSU rally, Southern coach Roger Cador discovered that Wahl, normally one of Southern’s best relievers, had hurt his foot while warming up.

‘‘It was unfortunate he went out there and didn’t tell us,’’ Cador said. ‘‘That’s the kind of thing you have to be conscious of with young people. They think they can carry the world on their shoulders when it’s a team effort.’’

LSU finished with 14 hits and took advantage of four Southern errors to score five unearned runs. LeMahieu had three hits and drove in two runs. Schimpf had three hits and scored the Tigers’ first run in the top of the sixth, stealing third base and advancing to the plate when catcher Michael Thomas’ throw went into left field.

‘‘Southern played so well for six or seven innings there, not just Richard pitching but the plays they made behind him were unbelievable,’’ Mainieri said. ‘‘When we were down 2-0, and it wasn’t looking so great, I was like, ’Thank goodness this is a nine inning game.’’’

Bertuccini (2-0) pitched 1 1-3 scoreless innings for the win and Buzzy Haydel pitched a scoreless ninth. But for Mainieri, the story was Ross, who is normally LSU’s third starter behind Louis Coleman and Anthony Ranaudo.

Ross gave up hits to three of the first four batters he faced, starting with Ozzie Lamis’ leadoff single and Franklin’s homer high over the right field wall. Ross also yielded a triple to Brad McDavid.

‘‘After that I kind of (bore) down and knew I had to keep them there and give our team a chance to win,’’ Ross said. ‘‘I knew that if I kept us there our lineup would eventually score some runs and get something going. I told myself, ’Don’t let them get anymore and we’ll be all right.’’’

From that point on, Ross registered nine of his strikeouts while allowing only four more hits and one walk.

Playing in its 23rd NCAA tournament, LSU is bidding for a 15th College World Series appearance and sixth national title. The Tigers were scheduled to play next on Saturday night against Baylor (30-24), which beat Minnesota 5-0 on Friday night.

Southern was slated to play an elimination game Saturday afternoon against the Golden Gophers (38-18).