Andy Murray recovered from a set down against Argentina's Pedro Cachin to book his spot in the quarter-finals of the Gijon Open.
The 35-year-old wildcard had battled past sixth seed Alejandro Davidovich Fokina in straight sets in the first round and followed that up with a 2-6 7-5 7-6[3] win on Thursday.
Cachin's first point of the contest came via a double fault from Murray, who struggled to recover from that setback as the Argentinian broke his serve right off the bat.
Murray then failed to convert three break point opportunities as Cachin came through a nervy second game to hold - helped by four aces - and the dominant 27-year-old would break again in the fifth game.
Cachin took under an hour to wrap up a comfortable first set, but Murray enjoyed more success on serve in the second set - winning 83% of his first-serve points compared to 55% in the first set.
No breaks would occur in the first 11 games of set two, but with Cachin serving to take it to a tie-break, a couple of unforced errors would hand Murray a seventh opportunity to earn his first break of the match.
The three-time Grand Slam winner made no mistake on that occasion as he forced a deciding third set, where both men broke in the first two games before Murray held for a 2-1 after a 17-shot rally.
Cachin and Murray would exchange back-to-breaks one last time as the third set went all the way to a tie-break, where the former world number one starred to bring up five match points.
Cachin saved two of them, one of which came on a Murray double fault, but the 35-year-old managed to see out a hard-fought win in two hours and 47 minutes.
Either Spanish third seed Roberto Bautista Agut or the USA's Sebastian Korda will face off against Murray for a spot in the semi-finals, where Pablo Carreno Busta or Arthur Rinderknech will be lying in wait.