Novak Djokovic and Rafael Nadal will meet for a record 43rd time on Saturday as the star pair battle for a spot in the final of the Monte Carlo Masters.
Nadal leads Djokovic 23-19 in the series which began nine years ago; the Spaniard, now fifth in the ATP rankings, won their last meeting in the Roland Garros final last June.
Top seed Djokovic crushed Marin Cilic 6-0, 6-3 in Friday's quarter-final, while eight-time Monte Carlo winner Nadal, slowly building up his form and confidence after a relatively poor previous 12 months, finally came through 6-4, 5-7, 6-2 against countryman David Ferrer.
Nadal, the third seed, struggled through in two and three-quarter hours after faltering when leading by a set and 3-0.
Djokovic won the first eight games against Croatia's reigning US Open champion who is seeded eighth but still coming back from months of shoulder problems.
Should he win the title on Sunday, Djokovic would become the first man to lift trophies at the opening three Masters 1000 tournaments of the season after completing the Indian Wells-Miami title double.
Gael Monfils continued into uncharted territory, with the Frenchman slugging Grigor Dimitrov 6-1, 6-3 for a career-first semi-final in the principality where he had never previously been past the third round.
The flamboyant Monfils followed up on his surprise victory against Roger Federer in the previous round while Bulgarian ninth seed Dimitrov came onto the clay as just a shadow of the player who knocked out holder Stan Wawrinka on Thursday with the loss of just three games.
Monfils, levelling his career in Monaco to 8-8, will next take on Tomas Berdych, who advanced into the final four as opponent Milos Raonic retired with a right foot injury.
Monfils stands 1-5 against the sixth-seeded Czech, who won his 26th match of the season when Raonic quit.
Sixth seed Berdych, now 2-3 against Raonic, spent just 31 minutes on court against an opponent carrying the existing handicap into the match.
Berdych has yet to drop a set this week and was in total charge through his brief encounter with Raonic, striking 10 winners and breaking twice.
Berdych will be playing in his 18th semi-final at the Masters 1000 level; he also played Monte Carlo semis in 2007 (lost to Nadal) and 2012 (lost to Djokovic).
