(Reuters) - Italian Filippo Zana of Jayco-AlUla won a gruelling stage 18 of the Giro d'Italia on Thursday after fending off Thibaut Pinot, while Geraint Thomas celebrated his 37th birthday in style by tightening his grip on the leader's maglia rosa jersey.
The 18th stage was one for the climbers on a 161-kilometre ride from Oderzo to Val di Zoldo, with Zana beating Pinot (Groupama–FDJ) to the finish line for his first Giro victory.
Warren Barguil (Arkea-Samsic) crossed the line third, well behind the top two.
Pinot and Zana were part of a six-man breakaway which built up a lead of four-and-a-half minutes to the peloton with 10km to go, but the duo dropped their companions on the steep Alpine slopes as they surged to the finish line.
In the overall standings, Ineos Grenadiers rider Thomas extended his lead at the top to 29 seconds, with Primoz Roglic (Jumbo-Visma) leap-frogging Joao Almeida (UAE Team Emirates) into second.
Thomas was made to work hard, as he clung to the wheel of Roglic throughout the final stretch, while Almeida did well to remain in touch of the pair after momentarily looking like he would be left behind by his GC rivals.
Thursday's stage served as a warm-up for Friday's punishing 183-km ride from Longarone to Tre Cime Di Lavaredo, which involves a long and slow climb at the start before three challenging category one ascents, with a total altitude gain of 5,400 metres.
(Reporting by Aadi Nair in Nashik, India; Editing by Toby Davis)