American World number 26 Jack Sock is through to the Delray Beach Open semi-finals after defeating Steve Johnson. Sock outclassed his compatriot Johnson in a straight sets battle 6-4 7-6 (7-4). The quarter-finals clash between Sock and Johnson lasted an hour and a half. Sock is bidding to win his second ATP title of the 2017 season as he made it all the way in Auckland back in January. Prior to this year's Delray Beach Open edition, the American was yet to make it past round 16 at the tournament held in Florida. He fired 7 aces and converted 3 out of 7 of his break point chances against Johnson.

On the other side, Johnson's career-best result of the season - the semi-finals of Auckland - has yet to improve.

Donald Young through without any fight

American tennis player Donald Young has reached the Delray Beach Open semi-finals. Young didn't have to put in any fight on the quarter-finals day on Friday, as Steve Darcis of Belgium gave a walkover to the American. The Belgian tennis player cited ''personal reasons'' for the withdrawal on his Twitter account.

Young is having a good month, reaching back-to-back semi-finals at the Memphis Open and now at the event in Florida. He was eyeing to win his career-first ATP title last week in Memphis - but fell short in the last-four stage to eventual champion Ryan Harrison.

The 27-year-old had a great run in Delray Beach two years ago in 2015 when he fell just short of winning the title after losing in the finals to Ivo Karlovic.

On the other side, it's an unfortunate ending for Steve Darcis, who did collect his best result of the 2017 season this week. ''Sorry that I have to withdraw from the Delray Beach Open quarter-finals.

Good luck to Donald Young,'' wrote Darcis on Twitter.

All set for an all-American semi-final in Delray Beach

Jack Sock and Donald Young will be squaring off in the Delray Beach semi-finals on Saturday. The two have met twice so far on the ATP level, with Sock ending on the winning side both times. The tournament's organizers should be happy, as the event will at least have one local player in the finals.