Southern Illinois' Randal Falker drives around Oklahoma State's Marcus Dove. SIU eliminated OSU from the NIT on Tuesday in Carbondale, Ill.

CARBONDALE, ILL. ? Matt Shaw scored 21 points and grabbed nine rebounds to propel Southern Illinois to a 69-53 victory over Oklahoma State in the first round of the NIT on Tuesday night.

The No. 4 seed Salukis (18-14) advanced to the second round behind an active defense that held the fifth-seeded Cowboys (17-16) to 35.3 percent shooting, including just 4-of-25 from behind the three-point arc.

Visibly flustered in their first trip to Carbondale in more than 40 years, the Cowboys struggled and were slow getting to the loose ball. Southern Illinois outrebounded Oklahoma State 22-8 in the first half and 39-21 in the game.

No one sent a message more on the offensive glass than Saluki forward Randal Falker, who repeatedly slammed errant balls into the basket.

Falker finished with 15 points and nine rebounds, with five coming on the offensive end. Joshua Bone added 11 points and Tony Boyle scored 10 points for the Salukis.

Guard Terrel Harris sparked the Cowboy offense early, scoring eight of the team’s first 10 points. But the Salukis kept him quiet for the rest of the half as he went 0-for-6 from long range.

Harris finished with a team-high 20 points. James Anderson added 13 for the Cowboys.

After trading baskets for most of the first half, Southern Illinois went on an 8-3 run to lead 26-19 at intermission.

Oklahoma State hit consecutive three-pointers after starting the game 0-for-13. But the Salukis were quick to respond both times, answering with three-pointers of their own on both ensuing possessions.

After the Cowboys went cold from outside, Southern Illinois stifled their presence inside with a defense that kept shots from the block falling off the side of the rim.

The Salukis played the game without starting point guard Bryan Mullins, who missed his first game of the season with a stress fracture in his leg.

Without their leading assist man, the Salukis committed several unforced errors early. But in his stead was Tyrone Green, a guard known more for his defense than ball-handling skills. Green finished with a career-high eight assists.

The victory was Southern Illinois’ first NIT victory since 2000. The team entered the NCAA Tournament in the six previous seasons before falling short of a bid this year.