CROCE D'AUNE, Italy (AFP) - Miguel Angel Lopez blasted lax security on the Giro d'Italia on Saturday (June 1) after he slapped a spectator who caused him to crash on the 20th and penultimate stage of this year's race.

The 25-year-old, wearing the white jersey as the best young rider, hit out twice at the man who cowered on the ground faced with the fury of the Astana rider who was brought down on the final mountain climb of this year's race.

"The fans should have more respect," fumed Colombian Lopez afterwards.

"I am sorry for my emotions, but in the rush of the race, especially in final of the queen stage it is hard to control it.

"It was pure adrenaline.

"I am very sad because of the bad security in the race, it's pity I lost my chances today because this situation happened."

The crash occurred on the final climb at Monte Avena, some 6km from the finish line, of the stage through the Dolomites in northern Italy.

A clearly frustrated Lopez got back on another bicycle but finished in 18th position, 1min 49sec behind Spanish teammate Pello Bilbao who won the stage.

"I regret not having the chance to go for the win," said the Colombian.

"I felt very good. I'm wearing the white jersey for the second straight year, I hope to defend it. But I came here with other ambitions."

Pink jersey holder Richard Carapaz now has one hand on the trophy as he leads former two-time winner Vincenzo Nibali and teammate Mikel Landa going into the final day, a time-trial around Verona.

Lopez, nicknamed "Superman", remains sixth overall but has lost time on his pursuers, notably Russian Pavel Sivakov, also a candidate for the white jersey.

Slovenian Primoz Roglic was punished after another spectator pushed him for up to 15 seconds on the penultimate climb at Croce d'Aune, without any objections from the Team Jumbo-Visma rider.

Roglic was issued a 10-second penalty when he crossed the finish line, and drops to fourth overall, 3min 16sec behind Carapaz.