Rafael Nadal produced another less-than-vintage performance at the French Open but it was still too much for Ivan Ljubicic.
World number one still misfiring while walkover puts Djokovic in semis
Rafael Nadal produced another less-than-vintage performance on Monday but it was still sufficient to defeat Ivan Ljubicic and reach the quarter-finals of the French Open.
The defending champion won 7-5 6-3 6-3 to face Robin Soderling - who beat Gilles Simon in straight sets - for a place in the last four.
Despite misfiring, particularly for the first set and a half, Nadal was too good for his 32-year-old Croatian opponent.
The first set was dominated by errors from both men, with Nadal giving back an early break before making a decisive move in the 11th game.
Given the apparent lack of confidence shown by the world number one so far in Paris, Ljubicic had been upbeat when assessing his chances before the match.
However, the veteran struggled to find anything approaching his best form when it mattered.
Ljubicic had beaten the Spaniard on two previous occasions, including at Indian Wells last year, and he battled well to hold his serve at the start of the second set.
But once Nadal had broken to go 4-3 in front, it was relatively straightforward for the top seed, whose game stepped up accordingly.
His shots, which had been sitting up invitingly, were now landing just inside the lines and biting wickedly into the clay.
Although Ljubicic briefly threatened a fightback in the third set, Nadal still had chances in every one of his opponent's service games and victory was secured in two hours and 26 minutes.
But Nadal does not believe he is currently playing well enough to win a sixth French Open crown this year.
Not confident
The 24-year-old said: "I am not confident. I am not playing well enough to win this tournament the way I played today. That's the truth. You have to be realistic.
"We will see after tomorrow if I am ready to play at this level. I am going to try. But I won five times already here. I don't have an obligation to win six. I am going to try for sure.
"Sometimes it's much more important to win when you are not playing that well than win when you are playing well, because winning when you are playing well probably it is easier."
Nadal will play Soderling in the last eight in a repeat of last year's final after the fifth seed saw off France's Simon 6-2 6-3 7-6 (7/5).
The Swede, who also reached the final in 2009, quickly silenced the fervent French crowd on Court Philippe Chatrier with an early break and never looked back.
There was little guile to the fifth seed's play, just relentless accuracy and even a third visit from the physio in three matches to treat a finger blister failed to slow him down against the 18th seed, although he laboured to close out the tiebreak to decide the match.
Meanwhile, Novak Djokovic advanced to the semi-finals at Roland Garros after last eight opponent Fabio Fognini was forced to pull out.
Fognini had booked a quarter-final showdown with the in-form Serb after overcoming Albert Montanes in a five-set epic.
However the 24-year-old Italian injured his left thigh during that win and he has now pulled out the tournament - handing Djokovic a bye into the last four.
Most difficult
"It's the most difficult decision I have made. It was my first Grand Slam," said Fognini.
"I was crying last night. But I had the treatment and I decided to retire.
"I had another scan this morning and we knew that to play would aggravate the injury to the left thigh. But this is sport, this is tennis."
Djokovic is unbeaten in 41 games this year - with a run of 43 straight wins - however he will not be credited with a victory over Fognini because the Italian withdrew.
He will now have four days off before facing either Roger Federer or Gael Monfils on Friday.
Ninth seed Monfils booked his place in the quarter-finals when taking his fourth match point to claim a 6-4 2-6 7-5 1-6 8-6 victory over David Ferrer.
It looked like the home favourite had blown his chance when he tightened up serving for the match at 5-3 in the decider and squandered two match points.
Ferrer duly broke back and then saved another match point on his own serve, but when Monfils moved 0-40 ahead in the Spaniard's next service game, there was no way back and the 24-year-old brought the crowd to their feet with a forehand winner.
The result, which means the Frenchman will face Federer in the last eight for the second time in three years, was something of a surprise given seventh seed Ferrer's form this year and it initially looked like he had taken control of the match on Monday.
Play was called off on Sunday night for darkness with the Spaniard 2-0 up in the fourth set and he raced through that to level the match but could not complete the job.
