STILLWATER, Okla. • In its unveiling as the nation's second-ranked team Wednesday at Gallagher-Iba Arena, Mizzou unraveled.

The Tigers tumbled 79-72 against a young and struggling Oklahoma State team by meandering early and crumpling late to leave a smattering of the crowd of 9,476 rushing the court.

"We didn't have the right mindset defensively in the first half. ... We didn't play the way we normally play in terms of being active and aggressive and coming up with the loose balls," MU coach Frank Haith said.

After trailing 37-36 at halftime, Mizzou (18-2 overall, 5-2 Big 12) hit the reset button and seized a 53-45 lead with 14 minutes, 21 seconds to go.

But in the last 6:30 of the game Oklahoma State (10-10, 3-4) outscored MU 26-12. On their best shooting night of the season, the Cowboys made nine of their last 10 field goals and MU missed eight of its last 12.

Many of Mizzou's shots in that sputtering sequence were somewhere between rushed and free-lanced, particularly as the Tigers fell behind.

That's contrary to the way MU's offense has been producing — by moving the ball until it finds a high-percentage shot.

"The guys went and tried to do their own thing a little bit," Haith said, adding, "We've got to get back to understanding that execution is so important, and one guy's not going to win the game. There's not a shot that's worth 15 points.

"And I sensed that a little bit, guys trying to go one-on-one and go make a play. ... That's pressing."

Oklahoma State features six freshmen among its nine regulars. But as Mizzou guard Kim English noted Monday, "Sometimes young guys can hurt you because of their obliviousness."

In fact, two freshmen had career highs, Le'Bryan Nash with 27 and Brian Williams with 22, to pave the way for OSU.

Asked about English's point, Haith said, "They played loose and easy, they had nothing to lose. ... But you know, when we're experienced, we've got to have an impact on them. We didn't play like an experienced team tonight."

A game after scoring a career-high 27 points against Baylor, Ricardo Ratliffe had 25 (and 12 rebounds) for the Tigers, including 19 in the second half.

Marcus Denmon added 17 on a night he was just four of 16 from the field in what seems to have become a shooting slump. He's made 23 of 67 in Mizzou's last five games and is 11 of 43 from 3-point range after hitting two of eight 3's on Wednesday.

"We came out in the first half and we didn't force our will on Oklahoma State," a concise Denmon said afterward.

Overall, the Tigers hit 40 percent from the field (26 of 65), while OSU shot nearly 60 percent (31-52, 59.6 percent). The Cowboys were making 40.9 percent coming into the game.

OSU led 37-36 at halftime on Keiton Page's jumper just before the buzzer, the last of 10 lead changes and five ties in the first 20 minutes.

OSU shot 57.1 percent (16 of 28) in the half as MU made just 14 of 34 from the field, with national field-goal shooting leader Ratliffe missing a season-high six shots in nine attempts.

He finished 10 of 17.

The Tigers opened the second half with an 8-2 run to take their first lead of more than three points on a Ratliffe follow of a Denmon miss.

They went up 53-45 on a three-point play by Ratliffe.

With 6:57 to go, OSU cut it to three on a Markel Brown dunk.

But Brown was called for his second technical of the game, resulting in his ejection, Denmon hit two free throws and Ratliffe added two more free throws off the ensuing possession to give the Tigers a 60-53 lead with 6:31 left.

Instead of being the beginning of the end for OSU, it was MU's cue to fade.

OSU made it 60-58 on a Nash jumper and his 3 with 5:42 left, and it went ahead 65-64 on his 3 with 3:22 left.

Twenty-six seconds later, he made it 68-64 on yet another 3, and a Page jumper made it 70-64 before a Ratliffe basket ended OSU's 12-2 run.

Mizzou cut it to four on two Ratliffe free throws with 1:09 left, but OSU went right back up seven on a three-point play by Williams, and the Tigers never got closer than five away down the stretch.

"I think we were avoiding contact as opposed to attacking," Haith said, adding, "I thought we were soft in our aggressiveness in going to the basket."

And that won't cut it for a No. 2 ranking.

"We understood that we're going to get Oklahoma State's very best effort tonight, and we did, we got their very best effort," Haith said. "They didn't get our very best effort."