Kei Nishikori, Marin Cilic, John Isner and Steve Johnson have made their way into the semi-finals of the Citi open.

The quarter-finals began with the American John Isner taking on Berankis. The American defeated Ricardas Berankis in three sets 3-6, 7-5, 3-6. John Isner maintained a high first serve percentage of 74 throughout the match. The 30 year old managed to hit 6 aces and converted one of his six break points to eerge victorious.

The second Quarter-Final featured the Americans Jack Sock and Steve Johnson taking on each other. Johnson who looked in ominous form took down his fellow countrymen in straight sets 7-6(5), 6-1. Steve Johnson managed to convert 3 of his five break points whereas Sock failed to convert one.

In the third quarter-final the 2014 US Open champion Marin Cilic took on the 18 year old German Alexander Zverev and the youngster looked mighty impressive by pushing the Croatian but wasn’t good enough to pull out an upset. He ended up losing to the Croatian in straight sets 7-5, 7-6(3).

The second seed Kei Nishikori took on the Australian Sam Groth in the final quarter-final encounter. Although the Japanese doesn’t had a good first serve percentage he managed to win most of the first serve points.He converted 2 of his 9 break points and ended up beating the Aussie in straight sets 6-4,6-4.

The first semi-final action features Kei Nishikori and Marin Cilic followed by John Isner and Steve Johnson.