Strikeforce: "Lawler vs. Shields" is officially a wrap. The event reportedly drew 8,867 spectators to the Scottrade Center in St. Louis, Missouri.

In the main event of the evening, former EliteXC welterweight champ Jake Shields defeated UFC and Pride veteran Robbie Lawler by submission in the first round of their 182 lbs catchweight bout. The submission wizard, Shields, came into the fight looking almost immediately for the takedown, however, Lawler was able to out-muscle Shields and keep the fight standing through two takedown attempts. Shields looked a bit uncomfortable when both men stood and struck at center cage, but just as Lawler was getting comfortable standing, Shields locked in a fight-ending guillotine choke while Lawler's head was down in the clinch. Lawler eventually tapped after he trying to slam out of the choke.

In the co-featured bout of the night, Brett Rogers pulled off a big upset victory over top-five heavyweight Andrei Arlovski just 22 seconds into the bout. A confident and determined Rogers unleashed a series of power punches on a retreating Arlovski. Moments later, Arlovski found himself up against the cage where Rogers rocked the Belarusian with a left hook, and then a right, that sent Arlovski to the mat causing referee "Big" John McCarthy to put a stop the contest. Rogers will now look forward to a possible title shot in August against Strikeforce heavyweight champ Alistair Overeem.

In the third featured bout of the night, UFC veteran Nick Diaz defeated Scott Smith by submission in the third round of their 179 lb catchweight bout. Diaz pummeled Smith for two rounds deftly mixing up punches to the head and the body while Smith seemed unable to string together more than one punch at a time. He collapsed at the end of the second frame due to a wicked body punch from Diaz. Smith tried to take the fight to the ground in the third round with a lazy shot, but Diaz immediately took Smith's back and locked in a fight-ending choke.

In the other main card bouts, welterweights Joe Riggs and Phil Baroni met in a welterweight showdown. Riggs was able to secure a decisive decision victory over Baroni by staying busy and controling the action both on the ground and standing up. UFC and Affliction veteran Mike Whitehead opened up the showtime telecast by defeating former UFC champion Kevin Randleman via decision.

In a notable preliminary card bout, Mike Kyle pulled off a hugh upset over top Strikeforce light-heavyweight contender Rafael "Feijao" Cavalcante.

Below are the official results for Strikeforce:"Lawler vs. Shields":

Main Card Results:

Jake Shields defeats Robbie Lawler by first-round submission (guillotine choke)

Brett Rogers defeats Andrei Arlovski by first-round knockout (punches)

Nick Diaz defeats Scott Smith by third-round submission (rear-naked choke)

Joe Riggs defeats Phil Baroni by unanimous decision

Mike Whitehead defeats Kevin Randleman by unanimous decision

Preliminary Card Results:

Jesse Finney defeats Josh Bumgarner by first-round submission (keylock)

Mike Kyle defeats Rafael Cavalcante by second-round TKO (strikes)

Booker DeRousse defeats James Wade by first-round TKO (strikes)

Tyron Woodley defeats Salvoder Woods by first-round submission (north-south choke)

Lucas Lopes defeats Scott Ventimiglia by first-round disqualification (illegal knee strike)

Pat Benson defeats Dave Cochran by first-round submission (triangle choke)