That the American was drawn against resurgent compatriot Sofia Kenin already represented a major hurdle - Kenin's current ranking of 128 belies her status as a recent former grand slam champion, and the 6-4, 4-6, 6-2 loss, although hard to swallow for seventh-seed Gauff, was no surprise upset.
Forget that Kenin had been forced to qualify for the main draw here. Both players have been ranked as high as world number four before injury and illness took their toll on Kenin, and there was little to choose between the two on a chilly night on Wimbledon's Court One.
"I am super happy," Kenin told the Court One crowd as dusk descended and after Gauff had left the arena.
"Coco played a tough match, and I knew I had to play my best match to win."
Moscow-born Floridian Kenin had begun the stronger, flying out of the traps with a barrage of groundstrokes taken super-early or at the top of the bounce, clattering them away for winners against her on-the-back-foot teenage opponent.
Gauff, herself a formidable ball-striker, steadied herself to edge the second set and restore balance, but it was Kenin who nosed ahead early in the decider and retained her grip, never allowing the increasingly frustrated 19-year-old another foothold.
"Point by point," Kenin said. "(Just told myself) don't get over anxious or super excited... I am just happy to finish before it got dark... Coco has had a great season and I am super proud of myself."
