SAN ANTONIO – Forget any of those thoughts about Greg Oden becoming a freshman flop in the NCAA tournament.

All that foul trouble Oden’s been in the last few games? Just a memory. The 7-foot sensation reasserted his dominance when he was needed the most – and Ohio State is going to the Final Four for the first time since 1999.

“When you have a guy like that that can block shots and have a presence and rebound like that, we had to play a perfect game,” Memphis coach John Calipari said.

In less than three minutes after Oden returned to the South Regional final Saturday with three fouls, the Buckeyes erased a five-point deficit. Everything changed when Oden got back on the floor, and Ohio State went on to a 92-76 victory over the Tigers.

“He came in with a lot of enthusiasm,” said fellow freshman Mike Conley Jr., also Oden’s high school teammate. “He saw things on the bench from a different perspective and he let us know that. He just picked us up.”

Ohio State (34-3) won its 21st straight game, now the nation’s longest winning streak. Memphis had won 25 in a row.

During the 4 1/2 minutes while Oden sat in the second half after his third foul, the Tigers went inside on almost every possession. They drove for layups or got to the free throw line.

Memphis couldn’t do that against Oden, who leaped high in the air to swat away the first shot attempted after he returned for the final 12:38 – and the Buckeyes finished with a 41-20 spurt that included 20 straight made free throws.

“I just wanted to go by the game plan, helping my teammates,” Oden said. “We all saw that it was coming to the end of the game, and we really wanted to go to Atlanta.”

In only 24 minutes, Oden scored 17 points on 7-of-8 shooting and had nine rebounds.

“Oden, when he was in there, just dominated, blocking shots and having presence,” Calipari said. “Thank goodness he was in some foul trouble.”

The Buckeyes have at least one more game, and they hope another, before Oden finally has to decide if he’s going to leave after only one college season for the NBA.

He would almost certainly be the No. 1 pick.

Oden has said he’s having fun and that “everything is easy about college.”

He insisted he won’t even think about the NBA until after the end of the season.

That almost came last weekend when Oden fouled out against Xavier with a hard shove in the closing seconds of regulation.

But Xavier made only one of two free throws, Ohio State senior Ron Lewis forced overtime with a 3-pointer, and the Buckeyes pulled away for a victory.

Oden was in foul trouble again Thursday night against Tennessee, when he played a season-low 18 minutes with only three rebounds. But he avoided another disqualification and was on the floor to block the final shot in an 85-84 victory.

Against Memphis (33-4), Oden had Ohio State’s last missed free throw. But even that came during a surge of five points in 2 seconds for the lead.

Joey Dorsey, the Memphis defender who called Oden “a lot overrated as a big man” the day before the game, was held without a point for the only time this season. He was fouled on the only shot he took – when Oden knocked him hard – and missed both free throws. Dorsey had only three rebounds, one after the first six minutes.

“Not smart. Not smart at all,” Jamar Butler said about Dorsey’s comments. “To come out and not score, that speaks for itself.”

Still, his teammates seemed more affected by the comments than Oden was.