Paris - Argentina's Juan Martin del Potro wept courtside after downing third seed Marin Cilic 7-6 (7/5), 5-7, 6-3, 7-5 on Thursday to set up a French Open semi-final clash with Rafael Nadal.
The injured-plagued former US Open champion battled through in three hours and 50 minutes after the match had been delayed by rain on Wednesday to reach the last four at Roland Garros for the second time, but first in nine years.
"It's tough to speak now," said an emotional Del Potro.
"I've been a long time without feeling good with my body. I had surgery three times on my wrist and I was close to quitting this sport. I don't have words to explain what this means to me and my team."
The fifth seed has now beaten Cilic eight times in a row, but on Friday he will face arguably the toughest test in tennis when he takes on 10-time champion Nadal for a place in the final.