Nikolay Davydenko became the highest-seeded casualty of this year's French Open after squandering a two-set lead against an inspired Ivan Ljubicic in the third round on Saturday.
The fourth seed, from Russia, raced out of the blocks but Croatia's Ljubicic launched a terrific fightback to prevail 4-6 2-6 6-3 6-2 6-4 in three hours and 13 minutes on Court One.
The former world number three, who is seeded 28 here after a lean couple of years, clinched victory with a slam dunk-style smash and will play unseeded Gael Monfils next.
Monfils, 59th in the world, defeated Jurgen Melzer 4-6 7-5 4-6 6-0 6-2 on Philippe Chatrier court.
The 21-year-old joins fellow Frenchmen Michael Llodra, Paul-Henri Mathieu and Jeremy Chardy in the last 16 in their home grand slam.
Earlier, fifth seed David Ferrer emerged victorious from a five-set epic against Australia's Lleyton Hewitt to edge through.
The Spaniard came through a topsy-turvy tussle 6-2 3-6 6-3 3-6 6-4 in more than three-and a half hours to set up a clash with in-form Radek Stepanek.
The match could have gone either way but in the deciding set, Ferrer picked up the key break in the ninth game and held his nerve to serve out for the victory.
Hewitt has struggled for fitness this year and believes matches like these will help him get in shape for Wimbledon, a grand slam he won in 2002.
'You can't come in and expect too much when I'm not 100% coming into the tournament,' said the former world number one.
'Hopefully it will help me going into Wimbledon. That's the biggest positive I will take out of it.
'If a couple of points had have gone my way, I could easily be through.'
Stepanek, the 21st seed, wasted little time in seeing off Spain's Tommy Robredo in straight sets.
The gritty Czech, who proved he is a threat on clay by beating world number one Roger Federer in Rome recently, demolished the 12th seed 6-3 6-2 6-1 in overcast conditions on Court Seven.
Stepanek has lost just one set in three matches at Roland Garros this year - and that was a tie-break in his second-round win over Jiri Vanek.
And he believes he could turn out to be the surprise of the tournament.
'I am definitely feeling comfortable on clay,' said Stepanek, who has made the fourth round for the first time here.
'I don't think there are many players left with a style like I'm playing.
'I believe I can play everything, from the back, at the net, serve and volley. I can mix up my game.'
'I was so aggressive from the first point (against Robredo) and I didn't let him do much.'
Big-serving Chilean Fernando Gonzalez came from two sets down to oust ninth seed Stanislas Wawrinka in another thriller on Saturday.
Wawrinka, who has enjoyed a superb 2008, made a great start on Court Two and looked in cruise control as he went 3-0 up in the third set.
But 24th seed Gonzalez dug deep and fought back to clinch a 5-7 2-6 6-4 6-4 6-4 victory and a last-16 match with Robby Ginepri.
Gonzalez, who has won clay-court titles in Munich and at Vino Del Mar this year, is undefeated on the surface in 2008, with a 14-0 record.
'This is a big win for me because I haven't played well at the French Open for many years,' said the 27-year-old, the runner-up at the Australian Open in 2007.
'But this year I have been playing well on clay - it's not my favourite surface but I've been having good results.'
The unseeded Ginepri kept the American flag flying at Roland Garros with a 6-4 6-4 6-4 win over France's Florent Serra.
The world number 88 is the first American to reach the last 16 here since Andre Agassi in 2003.
'I'm the last guy standing and it's a good feeling,' Ginepri said.
'I'm really trying not to let that weigh on my shoulders too much.'
Roger Federer disposed of Croatia’s Mario Ancic on Saturday to reach the last 16.
Federer took just over 90 minutes to clinch a 6-3, 6-4, 6-2 win over close friend Ancic, the last man to beat him at Wimbledon in 2002, but who has now lost their five subsequent meetings.
The Swiss star will face either France's Julien Benneteau or Robin Soderling of Sweden on Monday for a place in the quarter-finals.
Federer, who needs a Roland Garros title to complete a career Grand Slam, was completely untroubled by the 24-year-old Ancic who is still feeling his way back after missing six months of the 2007 season with glandular fever.
He broke in the fourth game of the first set and wrapped up the opener with an ace in the ninth game.
The second set was a similar story with a break in the seventh game while the top seed added further misery on to his opponent by breaking through in the first game of the third set.
Federer served two love service games on his way to a 3-1 lead and broke again to go 4-1 in the third as Ancic struggled in vain to stem the free-flowing hitting of the top seed.
The pair exchanged a break apiece to leave Federer 5-2 up before the Swiss claimed victory when Ancic went long with a return.
Saturday's results:
Gael Monfils (France) beat Juergen Melzer (Austria) 4-6 7-5 4-6 6-0 6-2
24-Fernando Gonzalez (Chile) beat 9-Stanislas Wawrinka (Switzerland) 5-7 2-6 6-4 6-4 6-4
5-David Ferrer (Spain) beat 25-Lleyton Hewitt (Australia) 6-2 3-6 3-6 6-3 6-4
Robby Ginepri (US) beat Florent Serra (France) 6-4 6-4 6-4
21-Radek Stepanek (Czech Republic) beat 12-Tommy Robredo (Spain) 6-3 6-2 6-1
1-Roger Federer (Switzerland) beat Mario Ancic ( Croatia) 6-3 6-4 6-2
