Cameron Norrie won four of the final five points to edge the deciding tie-break.
British number one Cameron Norrie avoided a shock defeat by Facundo Diaz Acosta as he fought back to reach the quarter-finals at the Argentina Open.
Norrie was on the brink of exiting the tournament but broke back as home favourite Diaz Acosta, ranked 191st in the world, served for the match.
World number 12 Norrie eventually edged a close deciding set in a tie-break to win 4-6 7-5 7-6 (8-6) in Buenos Aires.
The Briton meets another Argentine, Tomas Martin Etcheverry, next.
Norrie, 27, had trailed 3-1 and 5-3 as he was broken twice in the second set – but after taking the crucial ninth game the Wimbledon semi-finalist won three more without reply to force a decider.
He then had to stage another fightback in the tie-break, Norrie recovering from 4-1 behind to clinch his second match point and progress.
Norrie, who helped Great Britain reach the Davis Cup Finals in Colombia earlier in February, received a bye in the first round at the ATP 250 event.
World number two Carlos Alcaraz made a winning return from injury by defeating Serbia’s Laslo Djere.
Spaniard Alcaraz, 19, won 6-2 4-6 6-2 win over world number 57 Djere under the lights in Buenos Aires. It was his first victory since suffering an abdominal injury at the Paris Masters in November.
“It’s been a long time for me with no competition, with no matches, just recovering,” said Alcaraz, who pulled out of the Australian Open because of a leg injury and lost the number one ranking to Novak Djokovic.
Meanwhile, part-time player Matija Pecotic has bowed out of the Delray Beach Open in Florida.
The 33-year-old Croatian said he was going to “have to ask for another day off” from his full-time job in finance after a shock wins against former world number eight Jack Sock.
Pecotic lost his last 16 matches against the United States Marcos Giron, the latter progressing with a 6-3 6-3 victory.