Tsonga credits leg work to increased serve speed

Jo-Wilfried Tsonga of France managed to upset both top-seeded Novak Djokovic and No. 8 Andy Murray en route to the semifinals at the men's Rogers Cup in Toronto, a run owed in large part to his power serve.

"I'm just stronger. During practice, I've worked a lot on my legs," Tsonga told media members Friday after his match with Murray when asked how he generates so much velocity on his serve.  

Serving for the match, Tsonga released a 140 mph serve, followed by another at 147. His 7-6 (5), 4-6, 6-4 win took two hours and 18 minutes, seeing Tsonga unleash 18 aces on Murray.

Murray knew he would be in tough against Tsonga after the Frenchman's decisive 6-2, 6-2 win over Djokovic on Thursday.

"Jo is a top player," Murray said. "He's a fantastic athlete. When his game is on, he's very tough to beat."