Johnny Field's RBI double in the top of the 12th inning lifted Arizona to a 4-3 victory over Florida State in the College World Series on Friday night.
Joey Rickard had doubled into the left-center gap for the Wildcats' first hit off Florida State closer Robert Benincasa (4-2), who came on in the ninth. Field followed with his two-base hit to right, driving in Rickard.
The Seminoles scored two unearned runs off Arizona starter Kurt Heyer to tie it 3-3 in the sixth but had only three more batters reach base until the 12th.
Wildcats freshman closer Mathew Troupe (5-1) worked the last 2 2-3 innings for the win, striking out Devon Travis to end the game with a runner on third.
"Momentum is a huge thing, and being able to get that first win will carry us forward, and I think we'll ride the momentum Sunday and for the rest of the world series," Troupe said.
Arizona (44-17), which has won 14 of 16 games, plays UCLA on Sunday in a meeting of Pac-12 co-champions. The Seminoles (48-16) meet Stony Brook in an elimination game Sunday.
Field's game-winning hit came after he had gone 0 for 4 with a walk in his first five plate appearances.
"Tonight I wasn't really seeing the ball too well, had really bad at-bats early in the game, trying to do too much and chasing pitches that weren't in my zone," Field said. "The last at-bat I made adjustments, went back to the drawing board and tried to look for a pitch to hit the middle off of, and he just threw one over the plate and I was lucky enough to get my barrel on it."
Troupe hit Seth Miller with a pitch with one out in the bottom of the 12th to keep Florida State's hopes alive. Miller took second on a wild pitch and went to third on a groundout before Travis struck out swinging.
The No. 3 national seed Seminoles have lost four straight CWS openers since last winning a first-round game in 1999.
They scored a combined 35 runs on 24 hits in two-game super regionals against Stanford last week but found runs much harder to come by against Arizona starter Kurt Heyer and two relievers.
Only one of their three runs was earned. When they looked ready to threaten in extra innings, Arizona shut them down.
Travis was caught stealing after reaching base to start the 10th, and Justin Gonzalez was picked off first in the 11th.
Heyer, one week removed from a super-regional win over St. John's in which he allowed 17 hits over 9 1-3 innings, left after 7 2-3 innings. It was his 12th straight start that he has pitched into the eighth inning. He allowed three runs, one earned, on six hits and struck out eight.
FSU's starter, freshman left-hander Brandon Leibrandt, worked 4 1-3 innings and allowed three runs on six hits.
"Great one to win, tough one to lose," Arizona coach Andy Lopez said. "In a game like that — two good programs, two good starting pitchers competing like that — it's a shame somebody has to go home a loser."
The Seminoles tied it 3-3 with two unearned runs in the sixth. Jayce Boyd reached when third baseman Seth Majias-Brean's throw to first pulled Brandon Dixon off the bag. Heyer struck out Stephen McGee and Gonzalez, then walked Josh Delph before John Holland sent a drive into the left-center gap for a two-run double.
Arizona scored twice in the third against Leibrandt to go up 2-0. Rickard singled in a run and, after Gonzalez's two-out error at short, came home on Robert Refsnyder's base hit.
Sherman Johnson, who homered in the super regional-clinching win over Stanford last weekend, went deep leading off the bottom half to cut the Wildcats' lead to 2-1.
The Wildcats made it a two-run game in the fifth on another RBI single by Refsnyder.
The teams were playing each other for the first time since 1991 and the first time at the CWS since the 1986 championship game, which Arizona won.