The first day of the 2002 Las Vegas United States National Championships in Las Vegas was filled with action and excitement. What it lacked were the killer upsets that many previous National tournaments have provided in recent years.    Every single No. 1 seed in the men's competition, including both freestyle and Greco-Roman advanced to the semifinals as expected. The women's division featured an upset of one top-seeded wrestler, but also had strong performances by the other favorites.    You might call this year's U.S. Nationals as an event with some mini-surprises, which sets the stage for some remarkable matchups in the semifinal and final rounds.    Let's start with women's freestyle, the only style that lost a No. 1 seed. That happened at the lightest weight class, 105.5 pounds, where high school star Sara Fulp-Allen of the Peninsula Grapplers, the No. 8 seed, slammed the No. 1 seed Clarissa Chun of Missouri Valley in the quarterfinals, 8-1. Fulp-Allen turned 17 this year, making her eligible for the Senior level, and she has taken center stage in her very first U.S. Nationals. Fulp-Allen has drawn veteran Julie Gonzalez in the semifinals, the next floor on this fast-moving elevator.    With the upset out of the way, we can focus on some of the popular favorites. In men's freestyle, Cael Sanderson of Iowa State, the college legend who is becoming a national phenom, looks to be in top form at 185 pounds. Sanderson was the Outstanding Wrestler last year, but now that he has finished his college career undefeated, he is truly to main attraction. With fans crowding the mats every time he wrestled, Sanderson battered his opponents, with a pin and three technical falls. In the semifinals, he will face No. 4 Charles Burton of the New York AC, a rematch of last year's finals won by Sanderson, 4-1.    In Greco-Roman, the sport's greatest rivalry could be on target at 132 pounds, where a pair of Sunkist Kids, No. 1 Jim Gruenwald and No. 2 Dennis Hall, are setting a collision course. Gruenwald had a pair of technical falls, while Hall score two pins and a technical fall. In the semis, standing in the way of another Wisconsin war (both are native Wisconsonites, or whatever you call people from there....) are some talented challengers. Gruenwald faces No. 5 Joe Warren and Hall has No. 3 Glenn Nieradka in the semifinals.    Back to the mini-upsets. In freestyle, No. 10 Jeff Bedard of the U.S. Army made the semifinals, knocking off his talented teammate, No. 2 Jason Kutz, 4-1 at 132 pounds. Two athletes who moved up from 121 pounds, No. 5 Mike Mena of the New York AC and No. 6. Eric Akin of the Dave Schultz WC are also in the semis.    At 163 pounds, No. 7. Casey Cunningham of the Sunkist Kids delivered a knockout with a pin of No. 2 Donny Pritzlaff in 2:39 in the quarterfinals. His reward is a match with No. 3 Ramico Blackmon of Team Excel in an anticipated semifinal.    How about at 211.5 pounds, where No. 11. Nick Preston of Ohio International became a semifinalist with a 6-4 win over No. 3 Ryan Tobin of the Dave Schultz WC in the quarterfinals?    In Greco-Roman, the semifinals with the lowest seed will be  7. Justin Ruiz of Dave Schultz WC who beat No. 2 Dan Hicks of the U.S. Marines, 5-2 in the quarterfinal round. Those that know Ruiz would not be surprised, as he was one of America's top Greco-Roman Greco stars in high school before taking a mission and leaving the sport for a few years.    The women's draw featured the only unseeded semifinalists. At 112.25 pounds, unseeded Audrey Pang of PFW made the semis. There were two unseeded semifinalists at 147.5 pounds, Lisa Bisers of Pennsylvania and Cindy Herceg of Spartak.     What was exciting in the women's draw was the performance of talented high school stars. Joining Fulp-Allen in the semifinals were high school stars Brooke Bogren of Santa Fe WC at 121 pounds and Brandy Rosenbrock of Shamrock at 130 pounds. All three have excelled in USA Wrestling's age-group programs and have been waiting for an opportunity to test themselves against the older women. All three are setting sights on a great future in the sport on the Olympic level.    When there are not many upsets on the first day, there will be some tremendous showdowns between established stars on the second day. Stay with TheMat.com tomorrow and enjoy the best of the action at the U.S. Nationals.