American rapper Travis Scott was left stunned after witnessing a brutal knockdown while attending his first Power Slap event last week.<br /><br />Power Slap is a fighting promotion company owned by UFC president Dana White which puts on contests where competitors take turns to slap each other in the face.<br /><br />Despite its brutal nature, it has grown in popularity over the past year and has seen famous names such as Tom Brady and Charles Barkley attend events.<br /><br />Scott was in the audience for last Friday's Power Slap 6 show in Las Vegas ahead of the Super Bowl in the same city and sat next to White in the front row. <br /><br />He did not sit down for long, though, as he jumped to his feet when one particular smack sent a female athlete crashing to the mat.<br /><br />The camera panned around to get Scott's reaction, and he was visibly shaken by what he had just witnessed.<br /><br />Scott - who has had four No1 hits on the US Billboard Hot 100 chart - was seen looking around the arena as he struggled to comprehend what had just occurred.<br /><br />His reaction was very different from White's, who appeared to be smiling after the blow, while other audience members applauded.<br /><br />Power Slap has received criticism since its inception, with one expert slamming White for allowing defenseless fighters to take heavy blows to the head, risking serious injury.<br /><br />There have also been complaints about the money being paid to fighters after it was revealed when the show started that competitors were only receiving £3,200 per bout if they won.<br /><br />However, White has defended the brand, previously claiming that safety will be improved, while also stating that the pay is similar to what it was when the UFC first started.<br /><br />His events have still managed to attract some household names, but whether Scott will be back for another show remains to be seen.