Heat gets better of Bouchard

The tension mounted and temperatures soared at the US Open yesterday as top seed Novak Djokovic and Andy Murray set up a mouthwatering quarter-final, and Serena Williams made a 2014 grand slam breakthrough.

Temperatures neared 32deg Celsius in New York and hovered around 38C on the hard courts as high humidity tested players to the limit.

The sweltering conditions nearly sent out promising Canadian Eugenie Bouchard as the 20-year-old seventh seed had ice applied to her arms and legs and had her blood pressure checked during her fourth-round match before she was beaten 7-6 (7-2) 6-4 by Ekaterina Makarova.

‘‘I was feeling very lightheaded and dizzy on the court,’’ said Bouchard, who required on court medical assistance during the match. ‘‘You know, just seeing things a little blurry.’’

World No 1 Djokovic beat the heat by charging past 22nd seed Philipp Kohlschreiber 6-1 7-5 6-4.

‘‘It’s important obviously in these particular conditions not to get carried away by frustration of heat,’’ said Djokovic. ‘‘And especially after long rallies try to get extra breath.

‘‘Obviously when I won second set I wanted to get the job done in three.’’

Murray also made straightsets work out of his clash against Jo-Wilfried Tsonga, posting a 7-5 7-5 6-4 victory over the ninth-seeded Frenchman, who beat him in the quarter-finals at the runup tournament in Toronto.

Though Murray is seeded eighth after a sub-par season following last year’s back surgery, the Scot is approaching top form and has some positive memories of playing Wimbledon champion Djokovic in the grand slams.

‘‘I don’t feel like I’m that far away from playing my best tennis,’’ Murray said.

Top-seeded Williams turned back frustrations over a disappointing grand slam season by beating Kaia Kanepi to reach the quarterfinals.

Williams will meet Italian 11th seed Flavia Pennetta, who advanced with a 7-5 6-2 win against 29th-seeded Australian Casey Dellacqua.