Tsonga storms into last 16

Tokyo - Second seed Jo-Wilfried Tsonga blasted past Germany's Mischa Zverev 6-4 6-3 to reach the last 16 of the Japan Open on Wednesday.

The Frenchman will play countryman Richard Gasquet in the next round after the former top-10 player thrashed German Philipp Petzschner 6-3 6-2 on centre court.

World number seven Tsonga also tore through his opener, completing an easy victory with a forehand rocket into the corner before celebrating with a jig of delight.

"I've spent a lot of time in bed since last week," Tsonga told reporters after a punishing run of long matches in Bangkok culminating in a semi-final exit.

"I have a lot of energy and I feel good. I played great. Richard's a good friend and I'm happy for him to be back but I have a job to do against him."

A rejuvenated Gasquet showed glimpses of the form that took him to seventh in the world rankings in 2007 in his opening match at the $1.25m hard-court event.

"I probably won't be favourite against Jo," said the 23-year-old, who returned to major competition at the US Open following a ban for testing positive for cocaine.

"I'm trying to remake myself," added Gasquet, who was suspended for only 2 and a half months after a tribunal found he had been contaminated by kissing a woman in a nightclub.

Earlier, Latvian qualifier Ernests Gulbis upset sixth seed Radek Stepanek 6-4 6-4 to reach the last 16.

Gulbis, the son of a Riga business tycoon said to travel to some tournaments in a private jet, produced a superb display of controlled power to brush aside his Czech opponent.

"Unfortunately I started playing well at the end of the season," said the 21-year-old. "I was playing like a Spanish player -- two metres behind the baseline doing nothing."

Gulbis plays Juan Monaco in his next match after Spain's Guillermo Garcia-Lopez retired with illness at 5-0 down to the Argentine in their first-round clash.

Wednesday's matches were played under a closed centre court roof as typhoon rain lashed the waterfront venue.

The tournament has already lost its top seed after Juan Martin del Potro crashed out on Tuesday, losing his first match since beating Roger Federer in last month's US Open final.

The towering Argentine was the main attraction after world number one Federer and third-ranked Andy Murray pulled out.