But even the most hardened veterans can surprise themselves and the tall Argentine did so when he hung tough, slapped groundstrokes and eventually wore down Colombian Alejandro Falla 4-6, 6-2, 1-6, 7-6(5), 6-2 for a place in the final eight.
The Christian Bale look-alike has now won his last seven five-set matches and while the victory wasn't exactly pretty (he nailed 38 winners and committed 59 unforced errors), it was a significant one for a guy who is feeling every second of his advancing age.
Rolling back the years
"It's a surprise for me to be again in quarterfinals," said the former world no.15, who in 2004 fell to Britain's Tim Henman in the quarterfinals. "For the age. I'm 31, almost 32. I was winning some matches, having good ranking, but not in the Slams… I'm feeling younger now."
While he does not have an overwhelming powerful game and is not the fastest man on tour, Chela is a very efficient player of the ground, is smart, has variety and can paste winners to the open court. That's why in 2010, he finished in Top 40 for seventh year in the past nine, won two clay court crowns in Houston and Bucharest and became just one of four over-30 winners during the season .
This year, he reached his home nation final in Buenos Aires in February, but did little until Rome when he won two matches before falling to Florian Mayer. He picked up steam the week before Roland Garros at the World Team Cup, winning all four of his matches in straight sets.
Chela has been enjoying his career since he first came on tour, but the victories are sweeter past the age of 30. "Two or three years ago I was injured and it was very tough for me to come back to the top 50, and I think that's why," he said.
Chela will play the winner of the match between Andy Murray and Victor Troicki.