San Diego State right-hander Tyler Lavigne went seven and two-third innings, and allowed just three hits while striking out eight to lead the fourth-seeded Aztecs to the winners bracket of the 2009 Conoco MWC Baseball Championship with a 12-1 victory over fifth-seeded UNLV.

Lavigne (7-1) allowed six earned runs in five and and two-third innings in SDSU's 9-6 loss to UNLV on April 11. This time, Lavigne kept the ball down and pounded the strike zone and the Rebels never rattled the junior right-hander. UNLV starter Corey Hales (3-3) suffered the loss, allowing seven walks in two and two-third innings.

"The last time I elevated the ball up in the strike zone and they hit me hard," Lavigne said. "My focus was to keep the ball down in the strike zone and make them hit the ball that I want. My arm definitely felt pretty live."

The Aztecs, who had 15 hits, gave Lavigne enough support offensively through the middle innings and exploded with a seven runs in the eighth. SDSU's Erik Castro led the attack going 3-for-4 with two RBI and two doubles. Behind him in the order, Cory Vaughn was just as dangerous going 2-for-4 with two RBI and a double. They combined for back-to-back doubles and three RBI in the eighth.

"To win the first game for us is huge," SDSU coach Tony Gywnn said. "We've got a young team and I kind of sensed they were pressing early and then kind of settled in. We're into it now."

UNLV coach Buddy Gouldsmith said his team had trouble dealing with the shadows at the plate early against Lavigne and the sky played a factor in short left field on a pop-up-turned-double that keyed a two-run inning in the fifth.

"We had a really tough time picking up the ball early," Gouldsmith said. "For whatever reason our guys were coming back having a really tough time and felt his (Lavigne) ball was really getting on them in a hurry late because they weren't picking it up."

San Diego State (38-19), which has won eight of its last nine, advances to meet No. 2-seed New Mexico at 3 p.m. CT Wednesday. UNLV (26-31) falls to the loser's bracket and will meet No. 3 BYU in an elimination game at 11 a.m. CT Wednesday.