Irishman Eddie Dunbar secured a stunning last-ditch victory on stage 19 of the Vuelta a España as Spaniard Enric Mas maintained his overall lead with only one mountain stage remaining before Sunday’s finale.

The 30-year-old caught and passed Colombian Santiago Buitrago with just 300 metres left of the mountainous 210km slog from Vélez-Málaga to Peñas Blancas.

Bahrain Victorious rider Buitrago struck out for home inside the final 2km to distance his three breakaway companions, including Dunbar, who initially did not react. However, the Pinarello Q36.5 rider launched his counterattack in the final kilometre and wasted little time in reeling in Buitrago, who is the leader of the mountains classification. Dunbar finished 14sec ahead of Buitrago, with his British teammate, Thomas Gloag, coming home in third 23sec back.

“It’s incredible, I really didn’t expect this today,” said Dunbar. “I even said in the team radio after about 50 or 60km that today wasn’t my day. I wasn’t feeling good. Then I ended up in the break and my legs came around a bit.”

Movistar’s Mas comfortably held on to his 1min 37sec lead over four-time former champion Primoz Roglic as the overall contenders crossed the line together.

Roglic’s Red Bull-Bora-Hansgrohe team and the EF Education-Easypost outfit of former Giro d’Italia winner Richard Carapaz tried to increase the pace on the 18km final climb to the finish. However, they were unable to exert any pressure on Mas, who followed comfortably as he bids for a first Vuelta title after three previous second-place finishes.