Dubai, United Arab Emirates—Andy Roddick upset Rafael Nadal in the quarterfinals of the Dubai Tennis Championships yesterday, and then announced he had split with coach Jimmy Connors.

Roddick used his strong serve to beat the second-seeded Nadal 7-6 (5), 6-2, before revealing that Connors had resigned about a week ago because he wanted to spend more time with his family.

“I still have the utmost respect for Jimmy and thank him for his time,” Roddick said.

He credited the eight-time Grand Slam champion for having greatly improved his backhand and boosted his “fighting spirit.”

Roddick closed out the match against Nadal with one of 17 aces, and had multiple service winners against the Spaniard.

One of his aces measured 241 kph (149.75 mph), breaking the Dubai serve speed record he set a day earlier.

“I knew I was going to hit it well, from the first point. I kind of let it fly, and that’s what it took tonight,” said Roddick. “Anything less than that and I wasn’t going to win.”

Roddick had several love games in the match, using his powerful forehand to keep the Nadal at bay.

“The way he was serving tonight, it’s tough,” Nadal said. “You feel a lot of pressure when you’re serving.”

Nadal said he made too many errors on his forehands on crucial points. “Against a big server you have to put these balls in if you want to win,” Nadal said. “It’s disappointing for me today.”

Roddick will next face third-ranked Novak Djokovic, who beat Igor Andreev 6-2, 6-1.

“It’s going to be a big challenge for both of us,” Djokovic said. “Roddick has the strongest and probably the best serve in today’s tennis.”

Also on Thursday, Nikolay Davydenko defeated Andy Murray of Britain 7-5, 6-4 to reach the semifinals. AP