Steve Reid made a 22-foot shot from the top of the key with five seconds remaining as Purdue withstood a strong second-half comeback by Robert Morris and won, 55-53, in the first round of the NCAA Mideast Regional tonight.

"I looked up at the clock and saw single digits," said Reid. "I didn't want to panic and I wanted to make sure we got a shot off."

Reid, usually a substitute, led the Boilermakers with 20 points. He started because Ricky Hall was sidelined by a sore throat and headache.

The victory advanced Purdue to a second-round game with ninth-ranked Arkansas Saturday.

In the second game, freshman Robert Tatum's 15-foot shot at the buzzer helped Ohio University upset Illinois State, 51-49. The Bobcats play No. 12 Kentucky Saturday.

The Colonials (23-8) made up a nine-point deficit in the final 7:28. But Robert Morris' winning streak thus ended at nine games as Forest Grant's 45-foot shot at the buzzer bounced off the back of the rim.

Purdue (21-8) held a 50-41 lead before the Colonials rallied, using a pressing defense that produced a tie at 53 with 3:28 to play on a layup by Tom Parks.

"We felt like that (pressing) was the kind of game they could play, and we were afraid of it," Purdue Coach Gene Keady said.

Purdue held the ball until 22 seconds remained, called timeout and continued to hold it until Reid broke free off a screen at the top and sank the game-winner.

In the second game, Tatum's steal in the final 20 seconds gave the Bobcats (23-8) a lead, but the Redbirds (24-7) tied it with three seconds to play on a 20-footer by Raynard Malaine. Ohio called timeout, after which Tatum fielded a long pass in traffic around the free throw line and immediately put up his game-winner.

"I didn't think it was going in," said Tatum, who finished with 11 points. "The feeling was unbelievable."