Louisville (53-10), which is seeking its first College World Series title, will play Florida or TCU on Tuesday night. Texas AM (41-22) will play Florida or TCU in an elimination game Tuesday afternoon.
Fitch hit a two-run single off Aggies starter Corbin Martin during a five-run second inning, added a bases-loaded walk against Kaylor Chafin in the sixth and capped his third career four-RBI game with a bloop double in the eighth.
Fitch's walk gave the Cardinals a 7-4 lead and occurred after Bordner prevented Louisville from losing a 5-4 edge.
Bordner entered after Walker Pennington's RBI single made it a one-run game. After a sacrifice moved the runners to second and third, Bordner recorded a pair of fly outs to end the threat and pitched three hitless innings.
Louisville took a 6-4 lead when Logan Taylor reached on a fielder's choice grounder to second. Colin Lyman scored and the Aggies were unable to get the force at second when shortstop Austin Homan's right foot came off the bag.
Before the eventful sixth, the Cardinals took a 5-0 lead in the second by sending nine to the plate and getting six singles. Devin Hairston and Lyman preceded Fitch's base hit with run-scoring singles while Devin Mann capped the inning with a base hit.
Brendan McKay (11-3) allowed four runs and eight hits in five-plus innings. The first-round pick of the Tampa Bay Rays also was 1-for-5 and scored the Cardinals' first run.
Pennington and George Janca hit RBI singles in the fourth to make it 5-2. Blake Kopetsky made it 5-3 with a run-scoring double in the sixth.
Martin (7-4) allowed five runs and five hits in 1 2/3 innings.