LEXINGTON, Ky. - Hold the questions about Greg Oden’s future. Ohio State isn’t finished in the NCAA tournament.

Ron Lewis revived the Buckeyes’ national championship hopes with a long 3-pointer with two seconds left to force overtime, then Mike Conley Jr. dominated the extra period for a 78-71 victory over Xavier in a second-round South Regional game Saturday.

The Buckeyes’ rally from an 11-point deficit in regulation ensured the Oden era will last at least one more game.

Oden, the most coveted player to enter college in years, figures to be the first pick in the NBA whenever he decides to go pro. A decision on where the freshman intends to play next winter isn’t expected until after the season ends.

The Buckeyes are fortunate that time hasn’t already come.

“I’m hoping we can learn from this game and know we can’t just play around with teams in the first half,” Oden said. “Then the second half we’ve got to come at them and keep coming until the game is over.”

Ohio State trailed 55-44 with 7½ minutes left, and was still down 61-52 with 2:54 left. When Oden fouled out with a hard shove after Xavier’s Justin Cage rebounded an errant Buckeyes shots in the final 10 seconds, they looked lost.

Cage then made of one of two foul shots with 9.3 seconds left for a 62-59 lead, giving Ohio State its last chance. Lewis came down and, with two defenders flying at him, swished the tying 3-pointer from several feet beyond the arc.

“I was just trying to get an open look. I told Mike before we even left the huddle, ’Just give me the ball.’ That’s what he did. He found me,” Lewis said.

“That’s what I love about this team,” Ohio State coach Thad Matta said. “They give you, as a coach, a lot of confidence. I kept telling them, keep your confidence and make plays, and they did.”

With Oden on the bench, fellow freshman — and high school teammate — Conley took over. He scored 11 points in overtime and the Buckeyes (32-3) were never threatened again in winning their 19th straight game.

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The Buckeyes, who finished No. 1 in the final Associated Press poll, advanced to the round of 16 for the first time since they went to the Final Four in 1999 — an appearance later vacated because of NCAA probation. They will play the winner of Sunday’s game between Tennessee and Virginia.

Xavier (25-9), which has a history of knocking off higher seeds in the NCAA tournament, was unranked in the final AP poll.

MEN’S NCAA TOURNAMENT RESULTS Saturday’s games EAST REGIONAL Georgetown 62, Boston College 55 North Carolina 81, Michigan State 67 Vanderbilt 78, Washington State 74, 2OT MIDWEST REGIONAL Butler 62, Maryland 59 SOUTH REGIONAL Ohio State 78, Xavier 71, OT Texas A&M 72, Louisville 69 WEST REGIONAL Pittsburgh 84, Virginia Commonwealth 79, OT UCLA 54, Indiana 49

No one had to tell Ohio State about Xavier’s tourney reputation. Matta helped build it, serving as Musketeers coach for three seasons before leaving the Atlantic 10 school in 2004 to go to the Big Ten. His good friend, Sean Miller, took over at Xavier.

But this time, the Musketeers couldn’t quite get the job done after the 6-foot-6 Cage — using his quickness and experience as a senior to drive around and sometimes score over the 7-foot Oden — delivered eight points in a 16-3 spurt that gave Xavier a shot at an upset.

Cage, who led Xavier with 25 points, had a chance to all but win the game. He made his first foul shot but missed his second, and Ohio State had a chance to save its season.

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“I wasn’t nervous. I just shot them like I normally do,” Cage said. “It went in and out, so I just wanted to get back on defense and hope that they didn’t make it.”

Conley dominated the extra period. He scored Ohio State’s first seven points, then four free throws in the final 1:03.

Lewis finished with 27 points, going 4-for-5 from 3-point range and making all seven of his free throws. Conley scored 21 and Oden had 14 points, 12 rebounds, two blocks and two steals in 35 minutes.

“Any kind of situation you can think of, we’ve been through it as a team. Today was nothing different,” Conley said. “I had all the confidence in the world we’d win the game. We came too far to lose.”