Sascha Zverev outguns John Isner to reach Rome final

Alexander Zverev celebrates after his 6-4, 6-7, 6-1 victory over big-serving American John Isner. Photograph: AFP/Getty Images

Zverev, at 20, is the youngest on the ATP Tour since Novak Djokovic won Miami in 2007 at the age of 19.

Zverev will meet four-time champion Djokovic in the final after the Serbian crushed Austrian Dominic Thiem 6-1, 6-0 in yesterday’s second semi-final.

Earlier, with tennis greats Rod Laver and Manolo Santana looking on, the German showed off an all-court game that has prompted many experts to predict he’ll reach No.1 some day.

Zverev won most of the longer rallies, displayed a well-disguised drop shot, made precise volleys and even served bigger than Isner, who is usually one of the best servers on tour.

In the opening set, Zverev won 20 of his 22 points on serve to Isner’s 19 of 29, and over the course of the match he struck more aces: 12 to eight.

After losing a tight second set in which neither player dropped serve, Zverev responded by breaking at the first opportunity in the third.

Zverev improved to 3-0 in his career against the 24th-ranked Isner, who has been watching Zverev progress since they both trained at the Saddlebrook resort in Florida, when Isner was already a top pro and Zverev was an adolescent.

Earlier, Djokovic picked up right where he left off in a rain-delayed quarter-final against former US Open champion Juan Martin del Potro, closing out a 6-1, 6-4 victory.

Djokovic was leading 6-1, 1-2 before heavy rain on Friday forced a postponement. In clearer conditions yesterday, Djokovic held serve and then got the decisive break in the next game with a drop-shot winner. Djokovic waved his arms to get the crowd behind him as the set wore on, dictating play from near the baseline.

On the women’s side, fourth-ranked Simona Halep extended her clay-court winning streak to 10 matches as she advanced to the final by beating Kiki Bertens of the Netherlands 7-5, 6-1.

Halep will face 11th-ranked Elina Svitolina of Ukraine for the trophy after French Open champion Garbine Muguruza, pictured right, retired due to an apparent neck injury after only 20 minutes. Svitolina led 4-1. Svitolina won her tour-best 30th match of the year.

Defending French Open champion Muguruza’s injury scare comes just days before her return to Roland Garros. The 23-year-old defeated Serena Williams in France last year. The French Open begins on 28 May.

Svitolina said: “I just want to wish a fast recovery to Garbine, she has such a big tournament ahead in Roland Garros which is very tough as she’s the defending champion.

“It’s going to be very tough for her and hopefully she will recover quickly.”

After dropping five set points while serving for the opening set at 5-4, Halep started knocking her head with her finger as if saying, “Wake up.” After getting broken in that game she held at love in her next service game to end the set.

Halep then cruised past 20th-ranked Bertens amid intermittent rain.

Bertens committed 31 unforced errors to Halep’s nine.

Halep took the title in Madrid last weekend.