In an ultra-tight, all-American quarterfinal battle, No. 11 seed Alex Michelsen edged Christopher Eubanks 7-5, 6-7 (6), 7-6 (5) on Thursday at the Winston-Salem Open in North Carolina.

Michelsen served up eight aces with just two double faults. In a match where every break mattered, he converted 4 of 5 opportunities to break Eubanks' serve while saving 3 of 6 break points he faced.

Michelsen rallied from a 4-1 hole in the second set to take 5-4 and 6-5 leads, but Eubanks battled back to force the tiebreaker and extend the match, which wound up going nearly 2 1/2 hours. The third-set tiebreaker saw the opponents trade two points at a time before Michelsen clinched on his first match point.

Michelsen, who turns 20 on Sunday, drew one step closer to his first ATP Tour title and will face Spaniard Pablo Carreno Busta in the semifinals. Carreno Busta was a 6-4, 6-2 winner over American qualifier Learner Tien.

The other semifinal will pit No. 10 seed Lorenzo Sonego of Italy against David Goffin of Belgium. Sonego downed 15th seed Pavel Kotov of Russia 6-3, 7-5, and Goffin upset No. 16 seed Rinky Hijikata of Australia 6-1, 6-3.

--Field Level Media