Lewis pitched six quality innings and Kay added a pair of RBI hits as Houston upset the No. 4 Razorbacks 4-1 in the Houston College Classic at Minute Maid Park.
Kay hit a solo home run in the bottom of the third inning for his first career hit and added a RBI single in the fifth to give the Cougars a 2-0 lead.
"I looked like a genius today putting Cory Kay in the lineup, and actually that one came from my assistant coaches," Houston coach Todd Whitting said. "They wanted to give him a shot. He's done everything in practice that we asked him to do and he deserved a chance to play today. Sometimes you never know what a guy's going to do until you get him in the lineup, and he was outstanding today."
"I thought he did a good job but we had our chances," Arkansas coach Dave Van Horn said. "We didn't do a very good job at the plate. We swung at a lot of pitches and pulled off a lot of breaking balls. With a guy like that you've really got to stay through the middle. Give him credit; he did a good job."
Arkansas (10-2) put 10 runners on base Saturday, but didn't score until a Jacob Mahan fielder's choice RBI closed the gap to 3-1 in the seventh inning. The Razorbacks had the bases-loaded in the inning, but Houston reliever Codey Morehouse struck out Matt Vinson to end the threat.
Morehouse pitched three innings in relief, striking out four batters.
"He punched that guy out with a change-up," Whitting said, "and that takes some intestinal fortitude to throw that pitch right there."
Houston (6-4) added two runs on fielding issues for the Razorbacks. The first was on Chase Jensen's two-out infield hit scored Kay to give the Cougars a 3-0 lead in the fifth inning when three Razorbacks converged on the ball, leaving first base open.
Houston chased Arkansas starter Randall Fant in the inning. The left-hander failed to make it out of the fifth for the second straight weekend, giving up three runs on five hits.
"He threw four innings OK and that's kind of what happened last time," Van Horn said. "It's a situation where we've got to figure out if we want to start him or bring him out of the bullpen. If he can't give us a few more innings than that, we've got a few other guys out there. We'll be fine."
Cade Lynch limited the damage by striking out a pair of Houston batters in the fifth, but Arkansas gave up another run on a Tim Carver fielding error in the seventh. Carver failed to field a routine play cleanly with two outs, allowing a runner to score with the bases loaded, increasing Houston's lead to 4-1.
"A three-run lead is a lot bigger than two," Van Horn said. "Anything can happen in a two-run game. Three runs is almost like having a five-run lead (in that situation)."
Matt Reynolds singled and Sam Bates walked with one out in the ninth inning, but a Jake Wise groundout and Mahan strikeout ended the game.
"Where we got beat was we didn't get big hits from people in scoring position," Van Horn said. "We had a couple of innings where we had our chances.
"You're just hoping someone will hit one in the gap and get us close, and to the next hitter. It didn't happen."
Arkansas will face Texas on Sunday. It will be the first meeting between the longtime rivals since 2005.
Junior right-hander DJ Baxendale will start the game on the mound for the Razorbacks.