Chris Froome is set to become the first British winner of the Giro d'Italia and just the third man to hold all three of cycling's Grand Tours at the same time after surviving everything Dutch rival Tom Dumoulin could throw at him during today's penultimate 20th stage.
The Team Sky rider now only needs to avoid crashing during tomorrow's processional stage on the streets of Rome to be declared the winner.
The 214 kilometres route from Susa to Cervina today was won by Spain's Mitchelton-Scott rider Mikel Nieve after he dropped his fellow breakaway riders on the second of three tough climbs in the closing stages.
He crossed unchallenged to win in 5 hours 43min 38sec.
The Netherlands and LottonNL-Jumbo's Robert Gesink was second, 2:17 behind, while Austria's Bora-Hansgrohe rider Felix Grossschartner was another 24 seconds back in third.
The real action was unfolding further behind, though, as the general classification riders fought another pulsating dual following Froome's remarking 80 kilometres sole breakaway success yesterday.
Dumoulin, who started the day 40 seconds down in the overall standings, launched attack after attack in the final kilometres only for Froome to hold firm..
At one stage, the Team Sunweb rider appeared to have paid for his aggression when dropping behind his rivals before he fought-back and attacked the race leader yet again.
It proved an attempt in vain, though, as Froome extended his advantage to 46 seconds when crossing seventh today.
He is now within touching distance of joining cycling luminaries Eddy Merckx and Bernard Hinault in holding all three Grand Tours at the same time after his Tour de France and Vuelta a Espana wins last year.
Froome remains a controversial figure with some, however, given how is seeking to clear his name after failing a drugs test for having double the permitted levels of asthma drug salbutamol in a sample given during the Vuelta last year.
Colombia and Astana Pro Team's Miguel Angel Lopez rose to third overall, 4:57 behind Froome, after France's Thibaut Pinot was dropped today and tumbled down the leaderboard.
The race will conclude with a 115km flat stage in Rome tomorrow.