John Isner is having a fantastic week in Rome, as he won four consecutive matches on the clay surface. He defeated Marin Cilic 7-6 2-6 7-6 and reached the Internazionali BNL d'Italia semi-finals. His serve has been very efficient the entire tournament, and it brought him a success of his career in Masters 1000 tournaments on the clay surface. Isner will now face a young German star, Alexander Zverev.

Isner hit 21 aces in the match

Marin Cilic had 16 service games and didn't lose any of them, but Isner still managed to win this match. He won only 68 percent of the points played on his first serve, but he was very successful on the second serve, as he won 69 percent of those points.

Isner saved 4 of 6 break points in the match and didn't convert any of his two break points, but he dominated in both tie-breaks.

Isner won 8 of 10 points on Marin Cilic's serve in tie-breaks, as Croat couldn't find his game at that point. Also, he hit 21 aces and made just one double fault in this match. Isner found himself in a very uncomfortable situation in the tenth game of the final set when he was down 0-30 and was just two points away from defeat. But, he managed to find his serve and win the game. After that, Isner served his way into the tie-break and won it 7-2, as he reached his first career Masters 1000 semifinals on the clay surface.

A big opportunity

Josh Isner will face Alexander Zverev in the semifinals, a young and talented player from Germany, who beat Milos Raonic 7-6 6-1 in the quarterfinals.

Surely, Zverev will be a star in the future, and he is a big candidate to become a No.1 once in his career, but he is a good opponent for Isner at this moment.

A youngster has already played 12 matches this month, and he seems a little bit tired. Isner just needs to continue to serve this well, and he will have an opportunity.

Zverev just defeated a big server Raonic, so obviously he is a very dangerous player when it comes to returning the serve. He is not afraid to attack, so maybe Isner should play a serve-and-volley more often to eliminate Zverev's offensive skills. The match is on the schedule for tomorrow, not before 16:00 pm local time.

Rafael Nadal will play against Dominic Thiem in the third match of this quarterfinals, while Juan Martin Del Potro and Novak Đoković will finish this entertaining day in Rome, as they will face each other for the third time this season.

The final match is on the schedule for Sunday.