Steve Johnson edges Isner in 2 tiebreakers in Citi Open

WASHINGTON (AP) Steve Johnson weathered a total of 12 set points and withstood 29 aces from top-seeded John Isner to win their all-American quarterfinal at the Citi Open 7-6 (7), 7-6 (15) on Friday.

Johnson even won one point in the first tiebreaker by putting in play a 146 mph serve, then producing a lob winner over the 6-foot-10 Isner, a three-time runner-up at the hard-court tournament, including a year ago.

That terrific point came when Isner led 5-3 in the tiebreaker. He had a total of five set points he was unable to convert in the opening frame, and when he lost the tiebreaker on Johnson's forehand winner, Isner reared back and slammed his racket to the court, mangling the equipment.

The second tiebreaker was even longer and more excruciating for Isner, who held seven set points in that one, the first at 6-3. On the second, at 6-4, he got a good look at a short return by Johnson but yanked a forehand long.

Not quite the longest tiebreaker of the season – Isner lost one by an 18-16 score on grass at Queen's Club last month – it lasted 22 minutes, with plenty of openings for both players. It ended when Isner double-faulted for the only time in the nearly 2-hour contest to give Johnson his sixth match point, then pushed a forehand wide.

Johnson, ranked a career-best 25th this week, won despite never earning a single break point off the big-serving Isner. But Johnson did save all six break chances Isner accumulated and wound up with 22 aces himself.

They were two of the four U.S. men in the quarterfinals, the first time since 2003 that many made it that far in Washington.

Another member of that quartet, sixth-seeded Jack Sock, lost another two-tiebreaker match earlier Friday, beaten by 13th-seeded Ivo Karlovic of Croatia 7-6 (4), 7-6 (6).

Karlovic hit 26 aces, saved all four break points he faced and reached the semifinals in Washington for the first time since 2007. He'll play Johnson on Saturday.

Sock had a chance to force a third set Friday, holding a set point at 6-5 in the second tiebreaker. But Karlovic erased that with – what else? – a 133 mph ace, then delivered a 130 mph service winner to get to match point. He won when Sock's forehand clipped the net tape and sailed wide.

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