Outbursts, although infrequent, are welcomed by the fans and are even encouraged by coaches at a junior level.
Top-seed Novak Djokovic was tested by net-charging Spaniard Feliciano Lopez in a duel of volleys and passing shots before booking a berth in the semi-finals of the US Open.
On a hot, humid night at Flushing Meadows, Djokovic waged an entertaining battle with the 33-year-old serve-and-volleyer, before finishing off the 18th seed 7-2 in the fourth set tiebreaker to complete a 6-1 3-6 6-3 7-6(2) victory.
Lopez won 28 of 41 serve-and-volley points, while Djokovic countered with 33 forays to the net that produced 19 points for the world number one.
“He’s one of the rare players who actually serves and volleys after the first and second serves,” said Djokovic, winner of this year’s Australian Open and Wimbledon championships.
“He’s got a very big serve.”
Lopez served up 14 aces, while Dojokovic registered nine.
Djokovic, 61-5 with six tournament titles this season, will face defending champion Marin Cilic of Croatia in the semi-finals. The ninth-seeded Cilic advanced with a five-set win against France’s Jo-Wilfried Tsonga.
Cilic squandered three match points in the fourth set but was still proud of how he finished off a tough victory over Tsonga.
Trailing by two sets to one, Tsonga saved two match points in the 10th game to hold for 5-5 and another two games later to force a tiebreak that he won comfortably to set up the climactic fifth set.
However, the ninth-seeded Croat shook off the disappointment of failing to close out the contest by breaking the Frenchman to love for a 3-2 lead and held serve thereafter before cashing in his fifth match point for the win.