Video: Fans clash at US Open
Novak Djokovic had to ignore fans fighting in the crowd to join Roger Federer and Robin Soderling in the third round of the US Open.
A scuffle broke out between spectators on the Arthur Ashe Stadium midway through the first set of Djokovic's match with Germany's Philipp Petzschner, but the third seed ignored the distractions on his way to a 7-5 6-3 7-6 (8/6) triumph.
Second seed and five-time champion Roger Federer also had no trouble in advancing to the last 32, the Swiss star admitting he had enjoyed a "perfect start" to his campaign after taking just one hour and 41 minutes to beat Germany's Andreas Beck 6-3 6-4 6-3.
Fifth seed Soderling was another easy winner, beating American Taylor Dent in straight sets, but sixth seed Nikolay Davydenko was sent crashing out due to a sublime performance from France's Richard Gasquet.
Gasquet, who won the junior title at Flushing Meadows in 2002, claimed his first Grand Slam win of the year in the first round after early exits in Australia and Paris and missing Wimbledon with a rib injury.
And the enigmatic 24-year-old carried on where he had left off against Germany's Simon Greul, dismissing Davydenko by the same scoreline of 6-3 6-4 6-2.
Davydenko, who missed 11 weeks of the season after breaking his wrist in March, is the highest seed to fall in New York so far, joining seventh seed Tomas Berdych and ninth seed Andy Roddick in making an early exit.
A slimline Mardy Fish earlier continued his impressive form to power into the third round. Uruguay's Pablo Cuevas served for the opening set at 5-4 before Fish stormed back to win 15 of the next 17 games to complete a 7-5 6-0 6-2 victory.
After knee surgery at the end of September last year, Fish hired a nutritionist to help him get back into shape, the 28-year-old American subsequently losing more than two stone.
And his new diet has certainly paid off, with Fish winning back-to-back tournaments for the first time in Newport and Atlanta and finishing runner-up in Cincinnati where he lost to Roger Federer in the final after beating Britain's world number four Andy Murray and Andy Roddick.
"I really got aggressive with my training once I knew I was able to put in long hours and not get injured or have nicks and bruises and things like that which come up when you're probably not in your best shape," Fish said.
"And it really got fun. It got fun to practise. It's fun to try to outlast guys and it's fun to see when you play a match like today and you're in the heat and you crawl back and win that first set.
"You kind of look over in the changeover and see the guy has got the ice towel around his neck and he's probably not feeling that well. That's why you put in the work."
Fish will face France's Arnaud Clement in the last 32 after Clement's second-round opponent, Eduardo Schwank, was forced to retire hurt from their clash.
Clement had won the first set 6-3 and the scores were level at 5-5 in the second when Schwank decided he was unable to continue due to an ankle injury.
Spain's Albert Montanes also advanced to the last 32, the 21st seed enjoying an easy 6-4 6-3 6-1 win against Australia's Carsten Ball.