Australian No.1 Alex de Minaur could make a late push for a maiden appearance at next month's ATP Finals after a victory at the European Open in Antwerp.
Playing in his first match since the US Open quarter-finals, de Minaur showed his trademark fight to rally to a 2-6 6-4 6-2 win over Roberto Carballes Baena to book his spot in the last eight.
De Minaur is currently ninth in the ATP Live Race To Turin, 425 points behind eighth-placed Andrey Rublev, who is in action on Thursday in Stockholm.
The world's top eight will square off in Italy from November 10-17 where the champion collects $A3.3 million and, if he goes through the tournament undefeated, is in line for a payday of more than $A7 million.
The 25-year-old has battled a hip injury since Wimbledon, although he managed to play doubles at the Olympics then made a deep run at the US Open.
But the injury has continued to cause trouble, forcing him out of the Asian swing.
De Minaur said he was delighted to keep alive his European Open title hopes, after reaching the final of the event in 2020.
"It's never easy coming back from injury, so I am happy I was able to win today," said de Minaur.
"It took a lot of fight and effort, so I'm happy to get a first win here in Antwerp.
"The match is never over until the last point, that's what I always tell myself.
"I'm always going to compete until the very end and it's helped me win a lot of matches, so I better keep doing it."
After a sluggish start the Sydneysider found his groove in the second set with his serve troubling the Spaniard, winning 83 per cent (10/12) of points on his first serve.
The top seed will next face Frenchman Hugo Gaston, who survived a marathon encounter with Argentina's Mariano Navone 6-4 6-7 (3-7) 7-6 (7-4).
Earlier, veteran Spaniard Roberto Bautista Agut eliminated another Argentinian Tomas Martin Etcheverry 7-6 (7-2) 6-4.
Third-seeded Canadian Felix Auger-Aliassime closed the day by rallying past Hungary's Marton Fucsovics 6-7 (7-4) 6-4 6-2.
