Another two-out rally off Pettis in the 11th allowed the defending national champions to turn a 10-9 deficit into an 11-10 win in the first round of the NCAA Los Angeles Regional Friday at UCLA's Jackie Robinson Stadium.
The loss puts No. 21-ranked UCI (37-20) into an elimination game today at 2 p.m. against Kent State (39-24).
A bases-loaded double by pinch-hitter Trey Watkins just over the glove of retreating Sean Madigan near the right-field warning track, sent Pettis and the Anteaters walking off in disgust and, perhaps, disbelief Friday.
Watkins' blow was the last of a series of punches and counterpunches in a game that lasted four hours, three minutes and included 19 players for each team, 35 combined hits by 20 different players, 356 pitches and enough emotion to last an entire postseason.
"I really don't know how to describe it," LSU Coach Paul Mainieri said. "You don't see games like that very often."
Gillespie, who has guided 18 teams in regionals during 23 seasons as a Division I coach, was similarly overwhelmed.
"I'm sort of having a hard time remembering what all happened," said Gillespie, who called the loss difficult. "So much happened. It was a battle and I think everybody left it on the field. I'm extremely proud of how hard we played. We ask our guys to play every pitch and they did."
Every pitch had meaning in a game that had five lead changes.
Senior catcher Francis Larson hit two home runs and collected his fourth run batted in by delivering a squeeze bunt that gave UCI its final lead in the top of the 11th. Larson extended his school-record total to 24 career home runs.
The importance of Larson's second sacrifice bunt of the season, which traveled about 45 feet, might have eclipsed his two dingers that carried nearly a combined 800 feet over the left-field fence, because it put UCI on the verge of victory yet again.