Two of the least match-tough players in the Mutua Madrid Open draw had to be No. 3 seed Dominic Thiem and unseeded American John Isner.
Isner, who just turned 36, hadn’t even played outside Florida and Mexico all season.
Thiem went to Australia, and then the Middle East, but hadn’t played since then.
While Thiem looked as though he hadn’t missed a beat, Isner has come through a pair of third-set tiebreak victories over No. 9 Roberto Bautista Agut and, on Wednesday, No. 6 seed Andrey Rublev.
He fired 61 aces combined in those two matches.
And he beat Rublev despite having won significantly fewer points in the match.
It’s an intriguing quarterfinal match.