Canadian Milos Raonic's impressive run at the Estoril Open ended abruptly Saturday.
The 20-year-old from Thornhill, Ont., retired 41 minutes into his semi-final contest against Spain's Fernando Verdasco with a back aliment after dropping the first set 6-4. It came mere hours after Raonic advanced to his first-career clay court semifinal after downing fourth-seeded Frenchman Gilles Simon 7-6 (7-4), 4-6, 6-3 in a quarter-final match that took two days to complete due to darkness.
The second-seeded Verdasco also needed two days to down South African Kevin Anderson 6-7 (2-7), 6-2, 6-3 in a quarter-final contest which finished in rain.
Raonic was broken in the final game of his first set against Verdasco, walked to the umpire's chair and shook hands to signify he was retiring. He had six aces to that point but never broke Verdasco.
"I felt pain this morning," said Raonic, "It started as a small pain and got worse and worse.
"I want to win badly but I had to look at this from a mature standpoint. I don't want to push it too much. I don't know what would become of it and it's a long tennis year still to come."
Raonic said it was best he err on the side of caution.
"It's a tightness building in my back," he said. "But I have a good team around me and physios to treat this.
"I want to do as much as I can to help it heal quickly. I hope I can keep up the level I've shown over the last few weeks on clay."
Raonic had defeated Verdasco in their two previous meetings this season. Raonic earned his first career ATP title at the Spaniard's expense in San Jose in February, then defeated him the following week in an opening-round match in Memphis, Tenn.
After losing to Raonic in Memphis, Verdasco said he'd like nothing better than to get the Canadian on a clay court for a "real" match.
Verdasco will face Juan Martin del Potro in the final. Del Potro beat Pablo Cuevas 6-2, 7-6 (8-6) to advance to his second tournament championship of the season.
Earlier, the fifth-seeded Raonic had seven aces and five service breaks against Simon in a match that lasted a combined two hours 31 minutes.
Raonic captured the incomplete first set in a tiebreaker Saturday before Simon rallied to win the second.
Raonic stormed out to a 4-2 lead in the fourth but couldn't close it out as Simon saved two match points. But Raonic finally advanced on his third opportunity.