Birthday boy Geraint Thomas strengthened his grip on the leader’s pink jersey as Filippo Zana left Thibaut Pinot with a broken heart once again on stage 18 of the Giro d’Italia.

Thomas was able to follow a late move from Primoz Roglic on the approach to Val di Zoldo as Joao Almeida dropped back, and the two then worked together to keep the Portuguese behind and take 20 seconds out of him, enough to see Roglic move up to second.

With one mountain stage to come and a mountainous time trial before Sunday’s finale in Rome, Thomas leads by 29 seconds from Roglic with Almeida 39 seconds in arrears.

Italy Giro CyclingItaly’s Filippo Zana celebrated his first Grand Tour stage win (Massimo Paolone/AP)

“It was a decent day,” Thomas said. “To gain time on Almeida and not get dropped by Primoz, it was a good day, a solid day for sure. I felt pretty good, pretty in control.

“Primoz, he likes to go hard, then take it easy, then go hard. I gave him a few turns, then I wasn’t sure how he was feeling. In the last two kilometres he really squeezed on it again, he was super strong, but I was pretty happy with how it was.

“Obviously it’s nice (to gain time) but Primoz had a bad day the other day and Almeida did today. I’ve just got to keep being consistent day by day, climb by climb.”

The pink jersey crossed the line a little under two minutes after Italian champion Zana sprinted clear of Pinot, who for a second time in a week came within a few metres of a first career Giro stage win in his final appearance in the race.

The leading duo had been part of a six-strong breakaway group who were allowed an advantage of up to six minutes on the 161km stage from Oderzo, but eyes were always further back on the first of the mountainous trio of stages that will decide who wears pink in Rome.

Thomas, donning the leader’s jersey on his 37th birthday as he aims to become the race’s oldest ever winner, was clearly in confident mood as his Ineos Grenadiers team-mates drilled the pace on the front of the peloton.

They quickly shed several riders as the road ramped up inside the final 30 kilometres, first on the Forcella Cibiana, then on the steep slopes of the Forno di Zoldo.

There were question marks over Roglic’s form after he lost time on Tuesday’s stage 16 – a day when Almeida and Thomas rode away – but as they neared the top of the penultimate climb he showed his hand as Jumbo-Visma team-mate Sepp Kuss guided him to the front to launch an attack.

Thomas was quicky on his wheel but Almeida dropped back. Jay Vine did his best to guide his UAE Emirates team-mate back but could not fully close the gap after running wide on the short descent into the two kilometre climb to the finish, leaving Almeida to chase alone.

Irishman Eddie Dunbar finished just behind Almeida to move up to fourth overall, adding to the celebrations for the Jayco-Alula team after Zana’s victory.

While there was still no stage win for Pinot, similarly left frustrated on stage 13 last week, the Frenchman at least moved up to seventh overall, four minutes 43 seconds down.