Santiago Giraldo had never beaten a top-10 opponent in 19 previous attempts, but at the Madrid Masters, the 26-year-old Colombian took advantage of a lacklustre display by Andy Murray to make his breakthrough.
Giraldo won 6-3, 6-2 to reach his first Masters Series quarter-final and put a major dent in Murray's preparations for the French Open, which begins in just 16 days. The world No 8, who was playing his first clay-court tournament of the season, had beaten Nicolas Almagro in his opening match 24 hours earlier but will now go into next week's Rome Masters – his last scheduled tournament before Roland Garros – short of competitive play.
Although Giraldo has been enjoying the best run of his career during the current clay-court season, Murray had won both their previous meetings without dropping a set. On this occasion, however, there were only occasional flashes of Murray brilliance as Giraldo took control from the start, breaking serve at the first attempt.
Murray appeared reluctant to attack and made too many mistakes. Giraldo, in contrast, played with the confidence of a man who had already won 15 matches on clay this year and reached the final in Barcelona last month.
After losing the first set Murray started the second well enough, holding serve and then forcing his only break point of the match in the second game. At 1-1 and deuce, however, Giraldo hit a winner off a mis-hit and then broke as a Murray forehand clipped the top of the net and flew out. The world No 46 went on to book his quarter-final meeting with Spain's Roberto Bautista Agut in just 70 minutes.
Murray, who is looking for a new coach after his split with Ivan Lendl, blamed his defeat on inconsistency. "Sometimes in matches I'm playing really well for periods, and then other times not great at all," he said. "I need to become more consistent. My best tennis or my base level has to stay the same for a lot longer."
Asked what was missing from his game, Murray said: "My coach is missing. That's quite a big part of my team."
Rafael Nadal will face Tomas Berdych in the last eight after beating Jarkko Nieminen 6-1, 6-4. The world No 1 played well early on but limped over the finish line after a series of uncharacteristic mistakes.
"At 6-1 and 3-0 I was playing at my best level since Monte Carlo but then I slowed down a bit and made some errors," Nadal said afterwards.