ROME — Top-ranked Novak Djokovic regained his cool after throwing his racket off the court in a grueling, rain-delayed 4-6, 7-5, 7-5 quarterfinal victory over Stefanos Tsitsipas at the Italian Open on Saturday.

Djokovic fought back from breaks of his serve in each of the final two sets to reach his eighth consecutive semifinal at the Foro Italico — where he has lifted the trophy five times, most recently last September when the tournament was moved to later in the year because of the coronavirus pandemic.

"I'm just really, really glad to overcome this challenge," Djokovic said. "It's probably the toughest match of the year for me so far."

Djokovic didn't have much time to rest before he faces home favorite Lorenzo Sonego later Saturday for a spot in the final.

"I haven't played too many matches this year, so I don't feel too exhausted," Djokovic said. "I'm pumped to get another win today."

Sonego was backed by a loud crowd when he rallied past seventh-ranked Andrey Rublev 3-6, 6-4, 6-3 to reach his first Masters semifinal. Their match was washed out Friday.

Fans were allowed to fill 25% of capacity as part of the Italian government's reopening plan.

It was Sonego's second consecutive win over a top-10 player, after also eliminating No. 4 Dominic Thiem.

"It's an emotional moment for me," Sonego said. "I'm playing my best tennis."

Nine-time Rome champion Rafael Nadal was facing big-serving American Reilly Opelka in the other semifinal.

In the women's tournament, French Open champion Iga Swiatek beat two-time Rome champion Elina Svitolina 6-2, 7-5 to set up a semifinal later against 17-year-old American Coco Gauff.

Karolina Pliskova was playing Petra Martic in the other semifinal.

The Djokovic-Tsitsipas match began on Friday but was suspended overnight with Tsitsipas leading 2-1 in the second set and up a break — with play having already been interrupted for 3½ hours due to the intermittent rain.

"It kind of felt like we played two matches," Djokovic said. "The one yesterday, where he was a better player. He started also better today. I managed somehow to hold my nerves, break his serve in the important moments in the second and also third set.

"Completely different conditions today: ball bouncing a bit more, coming to you," he added. "Yesterday it was really slow and muddy on the court."

Djokovic also went the distance to beat Tsitsipas in five sets in last year's French Open semifinals.

This year's French Open starts in two weeks and Djokovic, who has had a difficult start to the clay-court season, appeared frustrated at times with his game.

Facing a break point early in the third set, Djokovic attempted a difficult drop shot that landed on top of the net cord and agonizingly bounced back into his side of the court — handing Tsitsipas a 2-1 lead.

Djokovic reacted by throwing his racket angrily into the advertising boards lining the side of the court, which drew a code violation warning for unsportsmanlike conduct from the chair umpire.

Djokovic's temper was also an issue during his second-round match this week against Taylor Fritz, when he fumed at the umpire for not stopping play soon enough due to rain.

Last year, Djokovic was disqualified from the U.S. Open for unintentionally hitting a line judge in the throat with a ball.

Djokovic's behavior once again drew attention away from his exquisite play and court coverage — which was effective even on points he lost.

During one particularly long rally, Tsitsipas ran down a drop shot then retreated to the baseline and eventually unleashed a powerful one-handed backhand down the line, to which Djokovic's forehand reply sailed long. That gave Tsitsipas a break of Djokovic's serve for a 5-4 lead in the third.

But Tsitsipas was left bent over, with one hand on his knee and the other leaning on his racket, which was resting on the clay.

Clearly exhausted, Tsitsipas couldn't then serve out the match.

Djokovic quickly took advantage and won three straight games to close it out after 3 hours, 16 minutes of play over two days.