Belmont Abbey committed seven errors, but the Crusaders pushed across the winning run on a wild pitch in the top of the ninth for a 6-5 win at Roberto Hernandez Stadium.
"I don't have any explanation for it," Thomas said. "It's been a weird year. It continues to be a weird year.'
With the defeat, USC Aiken (39-18) falls into the losers bracket and will face Tusculum in an elimination game at 11 a.m. today.
The Pacers lost their second consecutive contest at home. Last week, they dropped their Peach Belt Conference quarterfinal matchup to rival Augusta State.
Against unranked Belmont Abbey (35-24), USC Aiken committed two errors -- along with other fielding mistakes -- and had difficulty placing sacrifice bunts at times. The Pacers also left 10 men on base, including two in the bottom of the eighth.
"You have to execute," Thomas said, "when you have the opportunity."
USC Aiken starting pitcher Jason Cochcroft allowed four earned runs in 6Q innings. Reliever Chad Benefield allowed one run in 2w innings, but that run was costly.
The Pacers trailed 5-3 entering the bottom of the seventh before manufacturing a pair of runs. Alex Franklin, after getting hit by a pitch, stole second and sprinted to third on the catcher's throw into center field. Then, center fielder Justin Vasquez overran the ball, allowing Franklin to score.
In the eighth, Franklin hit an infield chopper with runners on the corners and two outs. Shorstop Josh Frazier overthrew first base, allowing Chris Grandinetti to score and knot the game at 5-all.
In the ninth, Belmont Abbey threatened with runners at second and third and two outs. Benefield worked an 0-2 count on Spencer Sabol, but then tried to waste a pitch -- one that bounced into the dirt and away from John Sherrer, allowing Patrick Atwell to score from third.
USC Aiken was trying to win its third game against Belmont Abbey this season. But the Crusaders served notice in the first inning when sophomore first baseman Daniel Kassouf slammed his 27th homer of the season.
Cody McMorris, Travis Howard, Nick Aranas and Grandinetti each collected two hits for USC Aiken, while ex-Evans star Ken Raborn homered.