Rafael Nadal will meet Novak Djokovic in the Monte Carlo Masters semi-finals after both men came through their last-eight matches on Friday.
Nadal remains on course for a stunning ninth title at the clay-court event after battling past David Ferrer 6-4 5-7 6-2.
A thrilling encounter between the two Spaniards featured a host of long rallies from the baseline, but Ferrer was let down by unforced errors as Nadal moved ahead after 53 minutes.
He maintained his form at the start of the second set to win the opening three games, but Ferrer fought back - despite struggling with blisters on his left foot - and levelled the match by winning four consecutive games having been 5-3 behind.
However, Ferrer was unable to keep his momentum going as Nadal upped the tempo in the decider, eventually prevailing to set up a mouth-watering semi-final with the world number one.
Djokovic was at his supreme best as he brushed aside the big-serving Marin Cilic, the top seed beating the US Open champion 6-0 6-3.
The 27-year-old barely gave Cilic a sniff in the opening set, the Croat winning nine points as Djokovic made a devastating start.
His intensity did not relent in the second and although Cilic managed to end an eight-game losing streak, there was nothing he could do as Djokovic glided around the court and picked his opponent off with ease.
The second semi-final will see sixth seed Tomas Berdych - who has lost in the last four of this event on three occasions - face an energised Gael Monfils, the wild card cruising past Grigor Dimitrov 6-1 6-3.
Berdych's progress to the last four was confirmed when his opponent, Milos Raonic, was forced to retire with a foot injury at 5-2 down in the opening set.