Sean Ochinko's three-run homer gave LSU the lead in the fifth inning and Ryan Schimpf's two-run blast in the eighth broke open the game for the Tigers, who beat Virginia 9-5 Saturday night in College World Series action at Rosenblatt Stadium.
LSU, ranked No. 1 in the major polls and the No. 3 national seed, extended its season-high win streak to 11 games.
The Tigers (52-16) play Arkansas on Monday night, with the winner of that game taking control of Bracket 1. Virginia (48-14-1), in the CWS for the first time, meets Cal State Fullerton in a Monday afternoon elimination game.
With LSU trailing 4-3, Micah Gibbs and Mikie Mahtook reached on singles leading off the bottom of the fifth. Ochinko then drove a 2-1 pitch from Matt Packer (3-5) into the left-field bleachers to put the Tigers up 6-4.
Franco Valdes' opposite-field home run to left off Austin Ross made it 6-5 in the seventh. Ross (6-7) and three other pitchers then combined to hold the Cavaliers to two hits and no runs the rest of the way.
Schimpf's 20th home run of the season, off Tyler Wilson, gave record-setting closer Matty Ott a four-run cushion when he went to the mound for the ninth. After he gave up a double to Valdes, Ott struck out Jarrett Parker to end LSU's first win in a CWS opener in four Omaha appearances.
The game matched former Creighton pitcher and current Virginia coach Brian O'Connor against his mentor and close friend, LSU's Paul Mainieri. O'Connor was Mainieri's pitching coach on Notre Dame's 2002 CWS team and when he left for Virginia in 2004, the two vowed to never play each other unless it was in the NCAA tournament.
The emotional meeting came on Division I baseball's biggest stage and lasted 3 hours and 40 minutes. The teams combined for 28 hits and went through a total of nine pitchers.
Gibbs hit a pair of RBI singles and LSU took a 3-0 lead in the third inning. Virginia, down 3-2, loaded the bases with one out in the fourth against LSU starter Anthony Ranaudo. Reliever Paul Bertuccini came on to strike out Phil Gosselin and then LSU left fielder Schimpf sprinted to his right to catch Danny Hultzen's liner to end the threat.
The Cavaliers went ahead in the fifth. Steven Proscia's homer to left center, his 10th of the season, tied it, and Keith Werman put Virginia up 4-3 when his liner went over the outstretched glove of second baseman DJ LeMahieu.