ROME — Novak Djokovic stayed on course to defend his Rome Masters title, reaching the semifinals with a 6-3, 6-4 win Friday over fifth-seeded Juan Martin del Potro.

Playing in sunny conditions with no wind, the third-seeded Djokovic was able to dictate play with well-angled winners from the baseline. Del Potro had trouble with his forehand, hitting the advertising banners lining the back of the court in one instance.

Djokovic had a 20-8 edge in winners while Del Potro committed 20 unforced errors with his forehand.

Djokovic will face either two-time Rome runner-up Roger Federer or German qualifier Mischa Zverev, who played later.

In the other half of the draw, three-time Rome champion Rafael Nadal faced eighth-seeded Fernando Verdasco for the first time since Nadal's epic five-set win in a match between the pair at the Australian Open. Also, No. 12 Fernando Gonzalez was up against Argentine qualifier Juan Monaco.

The Rome Masters is a clay-court warmup for the French Open, which begins in three weeks.

Djokovic improved to 4-5 against opponents in the top 10 this year. The Serb needs to defend his title to prevent Andy Murray from taking the No. 3 ranking from him, even though Murray was eliminated by Monaco on Wednesday.

Djokovic is the only player to take a set from Nadal on clay this year, losing to the Spaniard in the Monte Carlo Masters final two weeks ago.

Del Potro, who helped Argentina reach the Davis Cup final last year, has never reached a Masters Series semifinal on clay and dropped to 0-3 in his career against Djokovic.