John Isner fired down 43 aces at Queen's on Thursday and was still knocked out as Gilles Muller saved a remarkable 10 match points to progress to the quarter-finals.
Seventh seed Isner took the first set in London, only for Muller to edge two subsequent tie-breaks - the first a mammoth affair featuring 34 points - and prevail 3-6 7-6 (18-16) 7-6 (9-7).
Perhaps unsurprisingly, both players proved dominant on serve, Muller managing 26 aces of his own as he continued the good form he showed when reaching the final of last week's Rosmalen Grass Court Championships.
Top seed and defending champion Andy Murray overcame fellow Briton Aljaz Bedene 6-3 6-4 and will now face another countryman, Kyle Edmund, in the last eight.
Edmund was due to face Paul-Henri Mathieu on Thursday, only for the Frenchman to withdraw with a wrist injury.