Missouri Coach Brian Smith stepped off the mat, pumped his right fist in the air and unleashed a scream of joy.    "How ¤'bout them Tigers?" Smith said.    On a milestone night for Missouri, Smith had every reason to celebrate following his wrestling team's dual meet at Nebraska.    Missouri won its first Big 12 dual meet in school history and knocked off the Huskers for the first time since 1988 in a 24-16 Tiger win Saturday night at the Bob Devaney Sports Center.    "We are really excited about getting our first Big 12 win," Smith said. "This is a tremendous win for our program. Every match was critical - we knew it was going to be a dogfight."    The Tigers won their first conference dual since January 1994 when they beat Oklahoma 20-19 in a Big Eight meet. It was Missouri's second win over a Top 10 team this year. The Tigers beat then-No. 9 Illinois earlier this season.    Missouri (5-0), ranked 16th, won 6 of 10 matches to send No. 9 NU to its first loss in six duals.    "Missouri wrestled well," Nebraska Coach Mark Manning said. "They battled and won some close matches. We just didn't get it done. It's not the end of the world. We are going to keep getting better."    The turning point in the meet came at 141 pounds when Missouri's J.P. Reese notched a 9-5 win over Nebraska's Scott Burnett. With the bout tied 4-4, Reese scored a reversal with 44 seconds left in the match and followed by tipping Burnett to his back for a three-point near fall.    "That was big, but all the matches were big," Manning said. "We just need to show a little more fire out there."    The Huskers trailed 21-13 entering the final two matches, but still had an outside chance to rally with nationally ranked wrestlers Travis Pascoe (184) and Justin Ruiz (197) still left to compete.    Pascoe beat Dante Stone 12-6 to pull the Huskers within 21-16 in the team score before Ruiz, ranked fifth and needing a pin for NU to prevail, lost 13-8 to Missouri's eighth-ranked Scott Barker.    The Huskers also received wins from Jason Powell (125), Joey Malia (133) and Bryan Snyder (157).    "We need some guys to step up and perform," Snyder said. "Right now, nobody is doing that. It was a frustrating night."    Powell, ranked second, improved to 15-1 with a 5-1 win over Mark Bader. Malia supplied a spark by pinning Chris McCormick in 1 minute, 5 seconds. Snyder, ranked No. 1, stayed unbeaten at 17-0 by pounding No. 19 Kenny Burleson 22-9.    "We have a lot to work on as a team," Powell said. "We need more than four or five guys to be able to win as a team."    Other winners for Missouri included Kevin Herron (heavyweight), Jeremy Spates (149), Tyron Woodley (165) and John Kopnisky (174).    Nebraska also posted a 22-16 win over No. 24 Oregon State on Friday in Lincoln. Both teams won five matches, but the Huskers earned the win thanks to pins by Bryan Snyder and Justin Ruiz.    In another dual involving a pair of ranked teams, the No. 5 Iowa Hawkeyes opened their home season with a 27-10 win over No. 10 Northern Iowa in front of 6,251 fans Friday night at Carver-Hawkeye Arena in Iowa City.    Iowa is 5-0 while UNI dropped to 2-1.    The Hawkeyes won six consecutive matches from 174-133 to earn the win. Iowa won 8 of 10 matches in the dual.    Iowa earned pivotal wins at 174, 184, 197, heavyweight and 133.    At 174, Iowa's No. 12 Tyler Nixt beat Eric Hauan 6-4. At 184, No. 8 Jessman Smith of Iowa beat No. 9 Kyle Hansen 8-2. At 197, unranked Ryan Fulsaas of Iowa upset No. 9 Sean Stender 11-5. Iowa heavyweight Steve Mocco, ranked seventh, blanked No. 12 Paul Hynek 4-0. At 133, No. 8 Marc Juergens of Iowa won a wild 11-10 match over No. 18 Mark Manchio.    Second-ranked Oklahoma State rolled to a pair of dual-meet wins Sunday in Oregon, downing No. 24 Oregon State 38-3 before beating Oregon 30-3.    The Cowboys improved to 5-1 in duals. Their only loss was to No. 1  Minnesota.    Oklahoma State's Shane Roller (157) won by fall against Oregon State while teammates Johnny Thompson (133), John Mark Bentley (149), Tyrone Lewis (165), Pat Popolizio (184) and William Gruenwald (197) won by major decision.    Oregon State's only win came at heavyweight where No. 16 Jason Cooley beat No. 8 James Huml in overtime in the first match of the dual. The two wrestlers were deadlocked 1-1 at the end of regulation and continued on to a tiebreaker. Huml won the toss and chose down, but Cooley rode Huml out in the extra period to record the win.    In the win over the Ducks, Oklahoma State's Shane Roller (157), Pat Popolizio (184) and Willie Gruenwald (197) won by major decision.    Oregon's only win was a 3-2 win by Brian Watson over Ronnie Delk at 141.