Derrick Chievous had 35 points and 18 rebounds and freshman Doug Smith broke an 88-88 overtime tie with a slam dunk last night as Missouri beat No. 4 Oklahoma, 93-90, in Columbia, Mo.

The Sooners, 26-3 overall and 11-2 in the Big Eight, need a victory over Nebraska Saturday to win the regular season conference title outright.

Oklahoma overcame a 14-point halftime deficit to tie it, 84-84, in regulation.

After Smith's go-ahead basket, Missouri (18-8, 7-6) increased the lead to 92-88 when Chievous made two free throws with 27 seconds left.

Mookie Blaylock made two free throws to pull the Sooners within two and Lee Coward's free throw increased Missouri's lead to three. Ricky Grace's long three-point attempt at the buzzer fell short.

Long Beach St. 79, UNLV 77: Morlon Wiley made two free throws with one second remaining giving the visitors an upset victory over the No. 5 Rebels, their third loss at home this season.

Nevada-Las Vegas (25-4 and 14-3 in the Pacific Coast Athletic Association) was 72-4 at Thomas and Mack Center before this season. The Rebels already have clinched the PCAA regular season championship.

Long Beach State (17-9, 11-6) overcame a seven-point deficit in the second half as Wiley scored 18 of his 22 points.

Arizona 79, Washington St. 41: The No. 3 Wildcats were hardly pressed at home, providing Coach Lute Olson his 100th victory at Arizona.

Arizona led by at least 26 throughout the second half, twice taking 40-point margins.

Olson is 291-143 as a college coach at Long Beach State, Iowa and Arizona. He is 100-50 in five seasons at Arizona.

Purdue 84, Wisconsin 56: Troy Lewis scored 18 points and the No. 2 Boilermakers held the host Badgers to 16 first-half points in a Big Ten game in Madison.

Purdue improved to 25-2, 14-1.

Iowa 103, Michigan St. 87: Roy Marble scored 23 points and B.J. Armstrong 20, leading the No. 11 Hawkeyes in a Big Ten contest in East Lansing, Mich.

The victory improved the Hawkeyes to 21-7 overall and 11-4 in the conference. The Spartans fell to 9-16 and 4-11.

Brigham Young 89, New Mexico 82: Michael Smith scored 24 points and Jeff Chatman 19 as the No. 15 Cougars overcame an 11-point deficit in Provo, Utah.