Austrian cyclist Marco Haller unleashed an expletive-laden tirade against a spectator following Stage 12 of the Giro d'Italia on Friday (NZ time).
The fan tried to grab a drink bottle from the Katusha-Alpecin rider's mouth after the day's action had finished.
Haller reacted furiously, asking "what is wrong with you?" and spitting out a full array of colourful language before threatening to hit the spectator.
The man who tried grabbing the bottle was quick to apologise and security had to intervene before Haller rode off.
The 28-year-old was part of an early 25-man breakaway group, before eventually finishing the stage in 39th.
Slovenian Jan Polanc leads race favourite Primoz Roglic by over four minutes in the general classification, while New Zealand's Jack Bauer is 139th, but providing valuable support for team leader Simon Yates.