Former pro Alberto Contador beat Australian Lachlan Morton's time by two minutes and 37 seconds, ascending the required 8,848 metres in a time of 7:27:20.
The seven-time grand tour winner climbed 78 times up a one kilometre, 12 per cent average gradient segment called Silla del Rey in the Sierra de Guadarrama National Park (located in the Community of Madrid and Castile and León, Spain).
“Everesting madness completed," he posted on Instagram. "Thanks to your messages I was encouraged to do it.
"More than seven hours and 8,848 metres ascended; very demanding challenge but a very nice experience."
The 37-year-old was inspired to attempt the challenge as testing for his soon to be launched bike brand A Bikes.
The record has been confirmed by Hells 500, the official verifiers of Everesting challenges.