Fueled by a clutch pin by amazing true freshman Zack Esposito at 141 pounds, Oklahoma State held on to its No. 1 national team ranking in college wrestling with a 24-15 victory over No.2 Iowa, with 9,026 fans at Gallagher-Iba Arena in Stillwater.    With Iowa leading the dual meet 15-13, Esposito decked Luke Moffitt in 4:06, securing a pin after a scramble from a reversal in the second period.    Esposito's pin gave the Cowboys a 20-15 lead, which meant Iowa was still mathematically in the meet. However, Hawkeye Head Coach Jim Zalesky put in backup sophomore Chas DeVetter in for the final match instead of nationally ranked Ty Eustice. Cowboy Jerrod Sanders scored a 17-6 major decision over DeVetter in the closing match to send the Cowboy fans home happy.    "We needed (Esposito's pin)," said Oklahoma State coach John Smith. "That's how a tough dual meet goes. There were a few surprises in the dual, for sure."    "Esposito is a kid who expects a lot from himself, demands a lot from himself," said Smith. "Without question, we needed a momentum change after our national champion lost."    The national champion who lost was Johnny Thompson at 133 pounds, who fell to Cliff Moore 6-4 in overtime. Moore scored a takedown, lifting Thompson off the mat and winning the ensuing scramble. It was Iowa's third straight win after the half-time break, putting the Hawkeyes in a position to score a major comeback.    However, Esposito's pin and Sanders' major decision closed the door on Iowa for good.    "I put DeVetter in because Eustice was questionable," said Zalesky about the lineup change in the final match. "He was dinged in the head in practice last week. With the score 20-15, I didn't want a problem that would affect Eustice later in the season.    The bout started at 157 pounds where Shane Roller of Oklahoma State emerged with a tight 10-8 win over Joe Johnston. Roller scored a pair of first-period takedowns for a 4-1 lead. In the second period, another Roller takedown extended it to 7-1. However, in the final period, Johnston scored three straight takedowns, closing it to 9-8 with 13 seconds left. A Roller escape and solid defense ended the match at 10-8.    At 165 pounds, Cowboy star Tyrone Lewis fired up the crowd with an inside trip on the opening whistle, taking Matt Anderson right to his back. Anderson fought off the fall, but trailed 5-0 quickly. Two second period takedowns gave Lewis a 10-1 lead. With just eight seconds left in the bout, Lewis added a final takedown and with riding time secured a 13-1 major decision.    OSU made it three straight wins, and a 10-0 team lead, when Chris Pendleton edged Tyler Nixt, 5-3 at 174 pounds. This was a battle of wrestlers with national title hopes. There was no first period takedown, Pendleton scored an escape and takedown in period two for a 3-1 lead. The third period saw Nixt escape to close the margin to 3-2, but a Pendleton takedown on a scramble gave him a 5-2 lead and put the match away. Nixt escaped and attempted a takedown in a scramble on the buzzer, but to no avail.    Iowa broke through with a win at 184 pounds, as top ranked Jessman Smith scored a dominant 8-3 win over Jake Rosholt. Smith scored all three takedowns in the match and added riding time to cement the win.    At 197 pounds, Muhammed Lawal extended Oklahoma State's team lead to 13-3 with a strong 19-8 major decision over Ryan Fulsaas. Lawal had four takedowns in the opening period to establish control, and kept up the pressure from there. A Lawal takedown with 20 seconds left as well as riding time moved the victory from a decision to a major decision, a key team point at the time.    The halftime break included an announcement that OSU head coach John Smith was one of the first 10 athletes inducted into the FILA International Wrestling Hall of Fame. Smith was congratulated by members of the FILA Bureau, and received a rousing ovation from the fans.    Iowa came out strong after the mid-break with two big wins by their returning NCAA runners-up, and an upset win over a defending national champion.     Steven Mocco continued his torrid wrestling by quickly pinning Willie Gruenwald in 50 seconds at 285 pounds. A footsweep in the opening seconds put Gruenwald down, and Mocco ran an arm bar to a pin shortly thereafter.    At 125 pounds, returning NCAA runner-up Luke Eustice of Iowa used his ability to ride to defeat Skyler Holman, 2-0. Eustice scored an escape in the second period, then rode Holman out the entire third period to secure the victory.    Moore's upset of Thompson at 133 pounds put a scare in Oklahoma State's partisan crowd. Moore took a 4-3 lead with a takedown in the second period, and a Thompson escape in the third period knotted things at 4-4. When Moore lifted Thompson in the air with a double leg in overtime, the flexible Thompson attempted to work his way out of the takedown but was unable to counter out of it.    Esposito led 6-4 after one period at 141 pounds, and scored a reversal in the second period on a scramble. Shortly after, he locked up a pinning combination, put Moffitt away and basically claimed the win for the home team. When Zalesky did not send Ty Eustice out at 149 pounds, Jerrod Sanders shut the door closed.    "The last time I wrestled him he rode me out," said Esposito. "I realized I had to work on the bottom. It really wasn't a flurry. Those were comfortable positions for me. That last scramble, we go over that so many times in practice. Luckily, I got it and I got the fall for the team."    Veteran Tyrone Lewis provided the spark in the first half of the match, and freshman Esposito ignited the fire in the second half.    "Coach kept telling us in the locker room to score and keep scoring," said Lewis. "For me to execute and get the team rolling was a momentum starter."    Both Esposito and Lewis feel good about this Cowboy team, in spite of the upsets and close defeats in some matches.    "I think, as a team, we feel confident," said Lewis. "We feel we have momentum and confidence going into the National Duals next week. It will be top competition, and the opponents will be ready for us."    "This is a lot different than high school," said Esposito. "It is a lot more exciting. I have to keep it going. The team has to keep it going. We keep looking at the NCAA title. This is building to that. Hopefully we keep getting better.    Both coaches are looking ahead from this dual, mindful that the most important meet is in March.    "In the matches we were favored in, we wrestled tough. I thought Eustice and Moore wrestled well," said Zalesky. "I felt 174 was a big match. We had scoring opportunities on Pendleton but we did not finish. Tyler is right there with him. We can take a lot from this individually and teamwise. We have some things we can turn around."    "We were exposed with some serious deficiencies we need to focus on in the next few months," said Smith.     Perhaps, when these teams meet again, either in a dual or tournament format, the story will be different, but the intensity will remain the same.