American Steve Johnson rode on his purple patch as he ousted top seed John Isner 7-6 (9/7) 7-6 (17/15) to move on to the semi-finals of the Citi Open in Washington.
In a match that witnessed 52 aces, the fifth-seeded Johnson prevailed over his fancied compatriot in two tie-breakers that went on for almost two hours.
Johnson, who has lost just two off his last 14 matches on tour (including his solitary ATP title in Nottingham), had nerves of steel as he saved six break points and managed to pull off a duo of closely-fought tie-breakers to subsist his run without dropping a set at the tournament.
“My serve got me out of some trouble,” Johnson, who hit 22 aces, told ATP World Tour. “I was down love-30 a couple of times, was down love-15 when serving for the match.”
He added: “You never know how quickly these things can turn. I was fortunate to put in good first serves when I had to and I’m happy to be off the court instead of still playing.”
Up next for him awaits another big server in 13th seed Ivo Karlovic, who fired 26 aces en route a 7-6 7-6 win over Jack Sock. Johnson leads Karlovic 3-1 in career meetings.
Elsewhere, second-seeded Frenchman Gael Monfils shrugged off a stiff test from American Sam Querrey, winning 6-4 3-6 6-1 in an hour and 27 minutes.
Moving on, he is scheduled to cross the swords with Germany’s Alexander Zverev, the No. 7 seed, who upset fourth-seeded Benoit Paire 6-1 6-3 in the other quarter-final battle.
