Saturday 21 February 2015 08:53, UK
Donald Young toppled third-seeded Ukrainian Alexandr Dolgopolov 2-6 6-3 6-4 to book a semi-final showdown with Australian Bernard Tomic at the ATP Delray Beach Open.
Young, ranked 56th in the world, withstood 11 aces from the 24th-ranked Dolgopolov in a match lasting one hour and 56 minutes.
"I thought I fought well," said the American, who remains in search of a first ATP tour title.
"I didn't start off the way I wanted to. He was playing pretty well, hitting through the wind and controlling his shots quite good. I decided to buckle down, fight, go out swinging and got a little more not so conservative and it happened to work."
Young reached his fifth tour-level semi-final and his second in as many weeks after making the final four at Memphis.
Tomic, playing his fourth quarter-final of the season, ended the run of 19-year-old Japanese qualifier Yoshihito Nishioka 6-3 6-1.
Tomic saved all seven break points he faced to dismiss the 154th-ranked Nishioka in less than an hour.
France's Adrian Mannarino and Croatian Ivo Karlovic will contest the other semi-final after they came through their respective matches.
Fifth-seeded Mannarino, also targeting his first career title, came back to beat Yen-hsun Lu 3-6 6-1 6-1 in 90 minutes, while Karlovic routinely beat seventh seed Steve Johnson 6-2 7-6 (7-4).
Big-serving Croatian Ivo Karlovic edged a second set tie-breaker to oust American Steve Johnson 6-2 7-6 (7-4) and book his place in the semi-finals in Florida.
The fourth seed, who served 17 aces, remains unbroken for the tournament.
