Mason, Ohio: Unseeded American John Isner rallied from losing a first-set tiebreaker to upset seventh-seeded Juan Martin del Potro 6-7 (4), 7-6 (9), 6-3 in a grueling Western & Southern Open semifinal of Saturday.
Isner, who fell from No. 20 to 22 this week, will return to the top 20 after a stimulating Cincinnati run that includes beating three straight top-10 players for the first time in his career while earning his second Masters 1000 series finals appearance and first in Cincinnati. His previous Masters 1000 final appearance was at Indian Wells in 2012.
"It's awesome to be at this stage again," said Isner, who beat top-ranked Novak Djokovic in the quarterfinals and No. 8 Richard Gasquet in the second round. "I've been playing pretty well this season, but this tournament is where I've really started to put it all together. I'm playing pretty well in all facets of the game."