Oeiras - Stanislas Wawrinka struggled to set up a Portugal Open quarter-final against the host nation's man of the moment, with the Swiss second seed forced to fight through for a 1-6, 6-3, 6-4 win over Albert Ramos on Thursday.
The victory, which was sealed on a fifth match point, will cast 16th-ranked Wawrinka as the villain when he takes on Portuguese wildcard Gastao Elias, who won only the second ATP-level match of his career when he beat Denis Istomin 3-6, 6-1, 6-4.
Wawrinka, a semi-finalist on his Portugal debut in 2012, admitted that he might have arrived too early at the event where he had a bye into the second round and the latest possible start.
The Swiss even tweeted this week that he bought a PlayStation to help pass some of his free time after coming in last Friday night from Geneva.
"Maybe I arrived a bit early, but the first match of the tournament is always tough, especially if the guy already has played a match," he said of Ramos, whom he has now beaten four times including a February meeting in Argentina.
The Swiss made a fast recovery after world No 57 Ramos ran off with the first set.
But closing down the contest was tough, with Wawrinka failing on four match points in the penultimate game on his opponent's serve.
He finally got the win a game later after coming from 0-40 down.
"It's true I had my chances and maybe I was thinking some about those that I missed," said the 28-year-old, who is now coached by Swede Magnus Norman.
"I was focussing only on my own game.
"The most important thing was to win the match and that's what I did. I don't know much about Elias but I watched some of his match on TV.
"It's good for the tournament to have a Portuguese guy in the quarter-finals. I'll have to lift my level for sure."
The win for Elias came as the No 113 played in a main draw for only the second time this season.
In the women's draw, former French Open winner Svetlana Kuznetsova was a 6-2, 6-2 quarter-final victim of Swiss outsider Romina Oprandi.
"Unfortunately this was just one of those days where I wish I hadn't even stepped on the court," complained the 27-year-old wildcard who won the French Open in 2009, five years after lifting the US Open.
"It was just a horrible match, I haven't played that badly for a long time. Romina's style of play doesn't give you any rhythm to get into the match, which is a good tactic for her.
"My movement wasn't there today. I'm pretty sad about the performance."
Kuznetsova, who was playing the main draw at the clay event for the first time, lost in 63 minutes after never earning a break point and losing her own serve four times against the 53rd-ranked Swiss.
Oprandi will be playing in her third career semi-final at the WTA level, with her last appearance in a final four coming in the Netherlands in 2011.
"Of course I'm excited to be in a semi-final again, but I can't look any further ahead than the next match. It will be tough," the winner said of her Friday contest against third seed Anastasia
Pavlyuchenkova, who defeated compatriot and number seven Elena Vesnina 6-3, 6-7 (3/7), 7-6 (7/3).
That marathon took two and three-quarter hours, with the Martina Hingis-coached winner advancing with eight aces and five breaks of serve.
Spanish fourth seed Carla Suarez Navarro, the runner-up in 2012 to Kaia Kanepi, beat Monica Puig of Puerto Rico 6-2, 6-4.
Kanepi set up a re-run of the final from 12 months ago with a 6-4, 6-3 win over Japan's Ayumi Morita.
Results on the fourth day of the WTA/ATP Portugal Open on Thursday (x denotes seeding):
Andreas Seppi (ITA x3) bt Alejandro Falla (COL) 6-4, 6-0
Tommy Robredo (ESP x8) bt Robin Haase (NED) 6-4, 6-4
Gastao Elias (POR) bt Denis Istomin (UZB) 3-6, 6-1, 6-4
Stanislas Wawrinka (SUI x2) bt Albert Ramos (ESP) 1-6, 6-3, 6-4
Romina Oprandi (SUI) bt Svetlana Kuznetsova (RUS) 6-2, 6-2
Anastasia Pavlyuchenkova (RUS x3) bt Elena Vesnina (RUS x7) 6-3, 6-7 (3/7), 7-6 (7/3)
Carla Suarez (ESP x4) bt Monica Puig (PUR) 6-2, 6-4
Kaia Kanepi (EST) bt Ayumi Morita (JPN) 6-4, 6-3