MELBOURNE (AFP) - Jo-Wilfried Tsonga, Jarkko Nieminen and Mikhail Youzhny sealed quarter-final berths with four-set victories at the Australian Open on Sunday.

As the fans gathered their breath after Saturday's longest sixth day which didn't finish until 4:33am Sunday, it was more regulation at the halfway stage of the season-opening Grand Slam.

Second seed Rafael Nadal was scheduled to take on Frenchman and 23rd seed Paul-Henri Mathieu in the remaining evening fourth round match in the bottom half of the men's draw.

Tsonga cut down his second top ranked opponent of the tournament with a 6-2, 6-7 (5/7), 7-6 (8/6), 6-3 win over eighth seed Richard Gasquet in their all-French tie.

The 38th-ranked Tsonga, who sent ninth seeded Briton Andy Murray packing on the opening day, now faces 14th seed Youzhny, who won an all-Russian clash with fourth seed Nikolay Davydenko.

Youzhny, the number two ranked Russian behind Davydenko at 14, marched on with a 7-6 (7/2), 6-3, 6-1 win.

Finland's 24th seed Nieminen, the winner of the leadup Adelaide ATP tournament, finished too strong for German Philipp Kohlschreiber, who dumped Andy Roddick out in the previous round.

Nieminen worked his way through to a 3-6, 7-6 (9/7), 7-6 (11/9), 6-3 victory.

"I feel amazing, it's been a great start to the year," said the Finn, who will play either Nadal or Mathieu.

Tsonga, playing in only his fifth Grand Slam tournament, has been one of the revelations after his shock win over Murray and now close friend Gasquet.

"When you take a seed out in the first round you have his draw. So you have a better chance to play some unseeded players. So it's better, of course," 22-year-old Tsonga said.

"It's good for me because it's lot of confidence to beat a player (Murray) like that. He's very good. And for me, it was a test. When you beat somebody like that, you know you can beat a lot of guys."

Youzhny claimed his ninth consecutive victory after he winning the Chennai tournament on his way to the Australian Open.

"I played good today at almost everything," Youzhny said.

Davydenko, who remains at the centre of an investigation into a betting scandal following his defeat by Argentine Martin Vassallo Arguello last August, was bidding for his fourth consecutive quarter-final appearance.

In two third round matches carried over from Saturday, Juan Carlos Ferrero, seeded 22 and a former French Open champion, ended Argentine 10th seed David Nalbandian's tournament with a surprisingly comfortable 6-1, 6-2, 6-3 win in one hour 44 minutes.

Fifth seed David Ferrer took three minutes longer to oust American Vincent Spadea, 6-3, 6-3, 6-2.

They will meet in an all-Spanish fourth round match on Monday.