American Tejay van Garderen sprinted to a first Grand Tour victory ahead of Team Sky's King of the Mountains leader Mikel Landa on stage 18 of the Giro d'Italia, where Tom Dumoulin retained his overall advantage in the Maglia Rosa.

The 137 kilometres from Moena to a summit finish at Ortisei featured five categorised climbs through the Dolomites, which saw BMC Racing's Van Garderen pass Landa on the final corner of the uphill finish with Frenchman Thibaut Pinot third for FDJ, crossing eight seconds behind.

Dumoulin, meanwhile, stayed out of trouble to tighten his grip on the leader's pink jersey.

The Sunweb racer led Giro rivals Nairo Quintana and Vincenzo Nibali over the finish in ninth place, one minute and five seconds off the pace, so keeping his 31-second advantage over the Colombian.

Italian Nibali is one minute and 12 seconds off the pace in third place, while Pinot's bonus times saw him as Thursday's biggest mover, up to fourth on general classification.

Van Garderen, 28, was delighted after dashing ahead of Landa, who once again had to be content with a second-place finish.

"It has been a rough couple of years in Grand Tours as far as the general classification goes, but I did my best to try to keep the morale high. This is my first Grand Tour victory, so it's an incredible feeling," said the American.

Other than the tactics of the attacks on the climbs which Dutchman Dumoulin mastered, there was little other drama - although Movistar rider Quintana almost collided with a race motorbike during the trek up the Passo Gardena.

British rider Adam Yates ended in the white jersey for the leading young rider, taking it from Bob Jungels, and the Orica-Scott racer is now ninth in the overall classification.

Tom Dumoulin after he held onto his pink jersey on stage 18

Quintana had initially managed to get some distance on Dumoulin with an early attack.

Dumoulin, though, had closed back up by the time of the final climb and even produced a couple of threatening breaks himself as Van Garderen and Landa were left with a sprint to the line after getting clear of Pinot and Italian Domenico Pozzovivo.

The 100th edition of the Giro d'Italia will finish with a time-trial in Milan on Sunday, where Dumoulin is expected to be able to fend off any challenges from the climbers.

The Dutchman was left less than impressed with the approach of his rivals during Thursday's gruelling trek.

"I was feeling really good and did not lose any time to Quintana and Nibali, I did a little bit to the other contenders, because Vincenzo and Nairo were only focusing on my wheel," he said.

"It was a bit of a strange tactic because their podium spot is also in danger now, and I really would like to see them losing it because of this riding."

Friday’s stage 19 runs over 191km from Innichen/San Candido to Piancavallo.