Fourth seed Nikolay Davydenko threw away a two-set lead before going down 4-6, 2-6, 6-2, 6-2, 6-4 to Croatian Ivan Ljubicic in the third round of the French Open on Saturday.
Ljubicic, seeded 28th, will next face France's Gael Monfils, who beat Austrian Juergen Melzer.
"It wasn't physically demanding. It was more technically mentally demanding, because he was playing unbelievably in the first two sets, and he slowed down a little bit in the third," Ljubicic told reporters.
"I smelled the blood, and I said 'Well, now, let's try to hang in here'."
Davydenko, twice a semi-finalist in Paris, looked on course for a straightforward win after taking the first two sets in 75 minutes and by the middle of the third, the wiry Russian had not faced a single break point.
Ljubicic, who two years ago was third in the ATP rankings, stepped up a gear in the third set, converting his first chance in the fifth game and although Davydenko broke back, he stole the Russian's serve again to reduce the arrears.
The 29-year-old Croatian did not waste a crumb and converted the four other break points he was presented with to seal victory with a smash after three hours and 13 minutes.
Davydenko, the last Russian in the men's draw, struggled to explain his downfall.
"It's difficult to say, because in the first two sets he didn't play," the Russian told a press conference.
"I don't know what he did on the court, but he started to fight a little bit more and try to run. That's when I started to be nervous and to make so many mistakes."
Meanwhile, Roger Federer turned a potentially tricky outing against Mario Ancic into a stroll in the park, beating the Croatian 6-3, 6-4, 6-2 in the third round.
Ancic holds the distinction of being the last man to beat the Swiss maestro on grass, way back at Wimbledon in 2002, but that could not save him from being on the receiving end of a Federer masterclass on Saturday.
The Swiss conjured flowing winners with ease as Ancic tried every trick in the tennis manual, including playing a shot through his legs, to trip up the top seed.
But it was not meant to be and Federer set up a fourth-round date with either Sweden's Robin Soderling or Julien Benneteau of France after 95 minutes of one-sided action.