Rafael Nadal ensured he will keep hold of the world number one ranking going into the French Open with victory over Marin Cilic at the Rome Masters.
The Spaniard needed to reach the semi-finals to guarantee holding off Novak Djokovic in the rankings, and he did so with a 6-1 6-3 win.
Nadal goes on to face Richard Gasquet, who beat Tomas Berdych 4-6 6-2 6-4.
Djokovic will play Andy Murray in the other semi-final after beating Robin Soderling 6-3 6-0.
The Serbian, who extended his winning streak to 37 games, lost his opening service game of the match as Soderling immediately found his range with a couple of baseline drives.
But the world number two broke back in the next game and slowly began to wear his Swedish opponent down.
Djokovic reeled off the first three games of the second set before Soderling departed to the locker room with an apparent leg injury.
And when he returned, he had little answer to Djokovic who rattled off the three games he needed for victory.
Murray awaits in the last four after the British number one battled back from a set down to beat Germany's Florian Mayer 1-6 6-1 6-1 in Friday's opening quarter-final at the Foro Italico.
Top seed Nadal had almost withdrawn earlier in the week as he struggled with a virus but from the moment he struck a rasping forehand winner past Cilic to break serve in game two, it was clear the Spaniard was over the worst of it.
Nadal broke twice in each set as he powered to victory in one hour and 25 minutes and took a step closer to a sixth Rome title.
"I was lucky, I felt much better today," he said. "Yesterday afternoon I had fever but it improved at the end of the day. I still had a bit of fever this morning but it was fine before the match."
He added: "I improved today more than a little bit, I played better. First of all, to win a tournament you have to play well every day.
"I'm in the semis now. I've played three finals in a row on clay, I won two and lost one and now I'm in the semis again and that's very positive for me."
Nadal insisted the threat of losing the number one spot "played zero part" in inluencing his decison to play on in Rome.
"It was a tough decision to make because Roland Garros is very important for me," he said, "but I love this tournament along with Barcelona and Monte Carlo. It's a special time of the year."
In the women's quarter-finals, Denmark's world number one Caroline Wozniacki was pushed hard by Jelena Jankovic before coming through 6-3 1-6 6-3.
"I'm getting more and more comfortable on the clay," said 20-year-old Wozniacki. "You like to win quickly and comfortably but as long as you win it doesn't matter if it takes one or four hours."
She will meet seventh seed Maria Sharapova in the last four on Saturday.
The Russian lost the first set of her last eight match against third seed Victoria Azarenka 6-4.
But the Belarussian called a trainer on to the court to look at her right arm after losing the first game of the second set.
She was in some visible pain and eventually retired hurt at 3-0 down in the second set.
Sixth seed Sam Stosur beat home favourite and French Open champion Francesca Schiavone 6-2 6-4 in a repeat of last year's Roland Garros final.
The Australian will play fourth seed Li Na in the semi-finals after the Chinese player wrapped up a comfortable 6-3 6-1 victory over Hungary's Greta Arn.