Oklahoma 9, Oklahoma St. 8

Wednesday, May 17th 2000, 12:00 am

By: News On 6

OKLAHOMA CITY (AP) -- Jeff Bajenaru hit a big two-run homer in the sixth inning and worked out of a ninth-inning jam Wednesday as Oklahoma held off Oklahoma State 9-8 in the first round of the Big12 tournament.

The victory was Oklahoma's fourth in as many tries against OSUthis season. The Sooners (38-19) will play Thursday against the winner of Wednesday's game between Nebraska and Missouri. Oklahoma State (36-21) will play that loser in an elimination game.

Bajenaru's 11th home run of the season gave the Sooners an 8-5 lead after OSU had scored four times in the top of the inning to get back into the game.

He had to work for his 19th save. A three-base error by right fielder Elliot Joyner put Ryan Budde at third to start the inning. After a walk, Budde scored on a sacrifice bunt by Rob Watson that put the tying run at second.

A groundout moved the runner up before Bajenaru got Jimbo McAuliff to ground out to short.

Tommy Whiteman's RBI triple was the big hit in a two-run first inning that gave the Sooners early control against Matt Smith (8-7). They added single runs in the second and third and, after OSU scored once in the fourth, Oklahoma got two runs in the fifth to make it 6-1.

The Cowboys made things interesting in the sixth, scoring four times on five hits including a two-run double by McAuliff.

Then Bajenaru came through with his two-out homer. Both runs were unearned, due to a dropped ball by left fielder Carlos Gautreaux when he and shortstop Nebasett Brown failed to communicate on a popup.

Consecutive doubles by Budde, Darren Heal and Watson got the Cowboys within 8-7 in the seventh, and Oklahoma answered with one in the bottom half.

Evan Greusel (5-0) pitched 5 2/3 innings for the victory.