The junior third basemen went three for four with a double and a triple to lead UCI to a 3-1 victory that propels it into Monday's four-team winner's bracket semifinal against Vanderbilt (47-19) at 5 p.m. (PDT) at TD Ameritrade Park.
Sparks' triple into the left-center-field gap with one out in the eighth inning drove in Adam Alcantara to erase a 1-0 deficit. Sparks then scored the go-ahead and winning run on Chris Rabago's single up the middle.
It was the ninth triple of the season for Sparks, who takes over the sole NCAA lead in that department. It also made him 14 for 28 in postseason play since being moved from the cleanup spot to the top of the batting order.
The Longhorns (43-20), who left 12 runners on base, including 10 in the first five innings, broke a scoreless tie in the second inning with the benefit of some shaky defense by UCI starting pitcher Andrew Morales.
Morales, an All-American and the Big West Conference Pitcher of the Year, allowed six hits in six innings. He exited his NCAA-leading 19th start, his fourth of the postseason, after throwing 105 pitches. His five strikeouts gave him 141 this season, tops in the nation.
Senior Evan Brock, the Anteaters' No. 3 starting pitcher who had not made a relief appearance all season, earned the win. He took over for Evan Manarino with two on and two outs in the bottom of the seventh and retired the final seven he faced to improve to 9-6.
"Taylor Sparks had a spectacular game, both on offense and defense," UCI Coach Mike Gillespie said of the 2013 Big West Co-Player of the Year who was drafted No. 58 overall by the Cincinnati Reds last week.
Alcantara, a freshman left fielder who went two for four, singled to lead off the eighth off Texas starter Nathan Thornhill, who had blanked the 'Eaters on four hits through seven innings.
Justin Castro's sacrifice bunt moved Alcantara to second, before Sparks launched his 16th career triple, one off the school record.
Texas brought in closer John Curtis, whose first pitch was lashed into center field by Rabago, a junior shortstop, to put UCI on top for good. After junior first baseman Connor Spencer singled and junior catcher Jerry McClanahan struck out, sophomore designated hitter Jonathan Munoz singled to left, plating Rabago from second. Spencer was thrown out trying to advance to third on the play.
Brock struck out the side and allowed just one ball to be hit out of the infield to give UCI its first CWS-opening win. The 'Eaters dropped their opening game to Arizona State in 2007, their only other appearance in Omaha in which they were 2-2 and finished fourth.
"I haven't had much bullpen experience, at least this year," Brock said. "But definitely my adrenaline was pumping today, so, I mean, it was a big game."
Sophomore second baseman Grant Palmer went two for four with a double but was twice stranded in scoring position.
UCI, for which the leadoff man reached base in the first, fourth, fifth, eighth and ninth innings, left runners at third base in the first, second and fourth innings and stranded Sparks at second after he doubled with one out in the third.
Collin Shaw doubled to start the second inning to spark the Longhorns' lone scoring rally. He advanced to third on Madison Carter's sacrifice bunt to Sparks.
Shaw held at third when Morales fielded a softly hit bouncer up along first base, but Morales, with his back to Shaw, spun to look Shaw back after collecting the dribbler and then failed to set his feet in time to throw to first.
With runners at the corners, Zane Gerwitz dropped a safety squeeze bunt under the glove of Morales and Spencer to give Texas the early lead. Brooks Marlow followed with a single, but Morales struck out Ben Johnson, then induced senior All-American Mark Payton to ground out to limit the damage.
Morales walked the first two hitters in the first, before retiring the next three. He allowed a pair of two-out singles in the third, but struck out Kacy Clemens, the son of former Texas and major league great Roger Clemens, to end the threat.
After a one-out error and a walk in the Texas fifth, Morales retired the next two hitters to keep UCI within one. Morales worked his only one-two-three inning in the sixth.