BATON ROUGE, La. (AP) — Unfazed by sloppy play, unearned runs and an early deficit, LSU starter Anthony Ranaudo became the Tigers’ steadying force.

Ranaudo struck out nine and allowed one earned run in 7 2-3 innings, Ryan Schimpf hit a momentum-changing three-run homer, and LSU outlasted Rice 12-9 in the opener of the Baton Rouge super regional Friday night.

‘‘Ranaudo didn’t have his best stuff tonight, but he pitched like a warrior — the warrior that he is,’’ LSU coach Paul Mainieri said. ‘‘In the middle innings there, when we needed him to keep us in the game, he did.’’

By the time Ranaudo left with two outs in the eighth, LSU led 9-4, a record Alex Box Stadium crowd of 9,375 was on its feet, and teammates were climbing out of the dugout to congratulate LSU’s season strikeouts leader for his latest long outing in big game.

Ranaudo (10-3) increased his season strikeouts total to 147 — the seventh-highest single season mark in LSU history — while helping LSU (50-16) pull within a victory of a second straight trip to the College World Series.

‘‘In the beginning, we made a few errors and gave up some runs early, but the offense battled back and really carried us today and got a bunch of key hits in a huge inning,’’ Ranaudo said. ‘‘When guys make errors, I try not to let it bother me at all because I know that all year they’ve backed me up consistently and made great plays.’’

Three LSU errors — including a throwaway during a run-down — helped Rice take a 3-0 lead, all on unearned runs. The Owls (43-17) led 4-1 after Steven Sultzbaugh’s homer in the top of the fifth.

LSU responded with six runs in the bottom of the inning, highlighted by Schimpf’s homer that made it 5-4.

Oddly, the bunt sign was on early in Schimpf’s at-bat, when runners were on first and second base. Rice starter Mike Ojala, who’d struck out six and allowed only one run through the first four innings, bounced a pitch away from catcher Diego Seastrunk, moving the runners to second and third.

Rice head coach Wayne Graham decided to remove Ojala then.

‘‘He kind of lost his touch a bit,’’ said Graham, who brought in Taylor Wall, a lefty coming off a nine-inning, three-hit shutout against Kansas State in last weekend’s regional round.

The move seemed logical with Schimpf, a lefty, followed by another lefty, Blake Dean, in the LSU lineup.

Instead, Schimpf blasted a curveball over the wall in right-center for his 19th homer, giving LSU the lead for good. Dean followed with a single as LSU tacked on two more runs in the inning on Sean Ochinko’s double.

‘‘I wasn’t looking for a home run. I was just trying to drive something up the middle and stay through it,’’ Schimpf said. ‘‘Fortunately, I was able to put a pretty good swing on it and get it out there.’’

Schimpf later added an RBI double in LSU’s two-run sixth.

Wall (7-6) wound up with the loss, but Graham said he still could start Sunday if Rice wins Saturday to force a third game.

Ojala, pitching this season with torn ligament in his right elbow that will require surgery, retired the first six batters he faced, striking out four of them with a mix of changeups and curves.

LSU finally got a run in the fourth with the help of Ojala’s second balk and first hit batter. Ojala also hit a second batter before being pulled in LSU’s six-run fifth.

‘‘It’s bad news,’’ Ojala said, lowering his eyes disgustedly. ‘‘You can’t hit and walk people if you’re trying to win games. I thought I should have got myself out of many situations out there tonight. I couldn’t. There is not much to say about it.’’

Rice scored five runs after Ranaudo left, highlighted by Anthony Rendon’s 20th homer off the scoreboard behind the left-field bleachers in the eighth. But LSU held on without using closer Matty Ott, who’ll be fresh if needed later in the series.