Fifth seed Taylor Fritz defeated compatriot fourth seed Reilly Opelka in a three-set epic in the quarter-finals at the Atlanta Open on Friday.
Fritz, who reached last week's Los Cabos Open semi-finals and is currently ranked 36th in the world, edged out Opelka 7-6 (7-5) 6-7 (3-7) 7-6 (7-4) in just under three hours.
The pair sent down a combined 48 aces, with Fritz claiming 25 of them, with all sets going to tiebreakers, with no breaks of serve.
Third seed Cameron Norrie was bundled out by Finnish world number 78 Emil Ruusuvuori in straight sets.
Norrie, who won last week's Los Cabos Open for his maiden ATP Tour title, was beaten 7-6 (7-1) 6-3 by the Finn.
Ruusuvuori will take on teenager Brandon Nakashima in the semi-finals, after the American – who was runner-up to Norrie in Los Cabos - beat Jordan Thompson 7-6 (7-5) 7-5.
Sixth seed John Isner sent down 30 aces as he got past Australian qualifier Chris O'Connell 7-6 (7-5) 6-7 (3-7) 6-4.
Semifinals bound.— Truist Atlanta Open (@ATLOpenTennis) July 30, 2021
Taylor Fritz enters familiar ground, reaching the semifinals once again in Atlanta. After nearly three hours in a very tight match, he knocks out good friend Reilly Opelka, 7-6, 6-7, 7-6. #AtlantaOpen | #USOpenSeries | @Taylor_Fritz97 pic.twitter.com/KMnDbwURU2