Fifth seed John Isner crashed out of the Valencia Open in the first round to Spanish veteran Tommy Robredo 7-6 (7/3), 6-3 on Tuesday.
The American, who has only won two matches in four visits to Valencia, lost the opening set on a tiebreak after neither man could make an impact on the other's serve.
And world number 21 Robredo got the all-important break in the penultimate game of the match before serving it out for a first win over Isner in four attempts.
Robredo will face Chinese Taipei's Yen-Hsun Lu in round two.
The top three seeds David Ferrer, Thomas Berdych and Andy Murray all get their campaigns underway on Wednesday. – AFP