Seeded seventh and showing little problem with a surgically repaired foot, Raonic unleashed the third-fastest serve in tournament history on Wednesday. At 145 mph, it lags only Taylor Dent’s 148-mph record in 2010 and Andy Roddick’s 146-mph rocket of 2004.

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Despite the hammer delivered by Raonic, Germany’s Tommy Haas proved a difficult second-round opponent. Haas won the third set and forced a tiebreaker in the fourth before Raonic advanced 6-0, 6-2, 6-7 (5), 7-6 (4).

“I wish I had a serve like that even once in a match,” said Haas, who on Monday became the oldest man to win a Wimbledon match since Jimmy Connors in 1991. Haas is 100 days past his 37th birthday.

And yes, Raonic was impressed.

“He was playing a lot more aggressive and controlling more,” he told media members. “I was fortunate that I played well at the end of the fourth set.”

In a match which, by the way, ended at 2 hours, 34 minutes.

Next up for Raonic: No. 26 seed Nick Kygrios of Australia.

Other men’s winners Wednesday included No. 1 seed Novak Djokovic and American John Isner. No. 5 seed Kei Nishikori withdrew because of injury. Isner, seeded No. 17, ousted Matthew Ebden of Australia 6-2, 7-6 (8), 6-4 and unleaded 17 aces. A ball boy collapsed on the court during Isner’s match and was taken off on a stretcher, an apparent victim of the heat.

It was officially the hottest day on record at Wimbledon, topping 97 degrees. That’s nearly three degrees above 1976’s standard.