RIFUGIO PANAROTTA, Italy -- Julian Arredondo claimed the biggest win of his career with a solo victory on the 18th stage of the Giro d'Italia on Thursday, while Nairo Quintana retained the overall leader's pink jersey as the race returned to the mountains.

The 25-year-old Arredondo had been part of a breakaway and made his move with just under four kilometres (2.5 miles) remaining to ride alone up the summit finish to Rifugio Panarotta.

The Colombian had time to raise one arm into the air as he crossed the finish line, 17 seconds ahead of Fabio Duarte. Philip Deignan was 20 seconds further back at the end of the 171K (106-mile) leg from Belluno.

"It's a win that I've really searched for," Arredondo said. "I said it from the start, I'm in this Giro to win at least one stage, and it's from the start that I have been trying.

"Until today, I managed three second places and two third places, I was only missing a win and we got that today. We've tried so much and at the end we managed it. So tonight we'll celebrate."

Quintana remained 1:41 ahead of fellow Colombian Rigoberto Uran, with Pierre Rolland moving into third place as former race leader Cadel Evans slipped to ninth.

Rolland is 3:29 behind Quintana, two seconds ahead of Fabio Aru and Rafal Majka.

"Today was a calm climb, but there were several attacks, I managed to control all of them which concerned my position," Quintana said. "Each cyclist should worry about their own race. The team worked very well.

"I am very happy with how things are going, there is a good atmosphere, there is joy in the team. Also the Italians are cheering me on, they are supporting me during the race, I am very happy with the warmth that we are feeling on the Giro route."

A group of 11 cyclists escaped on the first categorized climb of the day, up San Pellegrino, and they managed to open up an advantage of 1:50 on the approach to the steepest part of the climb, which had gradients of 15 per cent.

Arredondo, who currently leads the King of the Mountains standings, attacked three kilometres (two miles) from the summit to pick up maximum points.

Deignan was just behind Arredondo, with Cataldo 40 seconds slower, but the breakaway was back together on the descent and three more riders joined it from the peloton.

The peloton hit the top of San Pellegrino four minutes behind Arredondo and the gap grew to twice that, with the favourites opting to conserve their energy.

The leaders maintained a significant advantage on the second climb -- the Passo del Redebus -- and had a 7:27 gap on the final climb of the day.

Thomas De Gendt attacked at the foot of the ascent, with 16 kilometres (10 miles) remaining, but the Belgian was caught and passed by Arredondo, Duarte and Deignan with six kilometres (3.7 miles) to go.

Back in the overall contenders' group, Rolland made his move with just over two kilometres (1.24 mile) remaining to move into a podium position, while Aru also gained time on Quintana with a final surge to the line.

Friday's 19th stage is an individual mountain time trial, which could prove crucial ahead of the Giro's final weekend.