Jai Hindley vowed to "die for" the maglia rosa in the final stage after he surged away from Richard Carapaz to lead the Giro d'Italia by a minute and 25 seconds on Saturday.
Alessandro Covi went solo to win a brutal stage 20 on the Passo Fedaia in his homeland, and there was huge drama behind the UAE Team Emirates rider.
Carapaz came into the penultimate stage with a three-second lead over Hindley, but his hopes of winning the prestigious race for a second time were surely dashed on a lung-busting final climb.
The INEOS Grenadiers rider cracked just under two kilometres from the end of the 168km route from Belluno, and Hindley capitalised to take the maglia rosa in the Dolomites.
Hindley is poised to become the first Australian winner of the Giro after he had plenty in the tank while Carapaz was suffering, finishing sixth having been given great support by BORA-Hansgrohe team-mate Lennard Kamna.
Kamna had been among a breakaway group but dropped back to assist Hindley on what looks set to be the decisive day of the race, which saw Koen Bouwman crowned the King of the Mountains.
The 2019 champion Carapaz crossed the line in 11th on a painful day for the Ecuadorian, with Mikel Landa remaining third in the general classification after finishing ninth.
With only a 17.4km time trial to come in Verona on Sunday, Hindley is ready to make history
He told Eurosport: "I knew this was going to be the crucial stage of the race, I knew it was a brutal finish and if you had the legs you can make a difference.
"It was perfect with Lennard up the road in the breakaway, and he couldn't have timed it better to drop back in help. When I knew Carapaz had cracked, I just went all out."
Asked if that should be mission accomplished, Hindley replied: "We'll see how it goes, it's always hard to say how a time trial will go on the last day of a three-week race. I'll die for the jersey."
Deja vu but surely no denying Hindley this time around
Hindley was wearing the maglia rosa at the start of the final stage two years ago but finished second behind Tao Geoghegan Hart.
It was a different story in 2020, though, as the 26-year-old did not have a time advantage to play with.
Hindley was a man on a mission on Saturday, and he will surely not be denied a maiden Grand Tour title this weekend.
It was also a day to remember for Covi, who secured a maiden Grand Tour stage win, finishing 32 seconds before Domen Novak.
1. Alessandro Covi (UAE Team Emirates) 4:46:34
2. Domen Novak (Bahrain Victorious) +0:32
3. Giulio Ciccone (Trek-Segafredo) +0:37
4. Antonio Pedrero (Movistar) +1:36
5. Thymen Arensman (Team DSM) +1:50
1. Jai Hindley (BORA-Hansgrohe) 86:07:19
2. Richard Carapaz (INEOS Grenadiers) +1:25
3. Mikel Landa (Bahrain Victorious) +1:51
1. Arnaud Demare (Groupama-FDJ) 254
2. Fernando Gaviria (UAE Team Emirates) 136
3. Mark Cavendish (Quick-Step Alpha Vinyl) 132
King of the Mountains
1. Koen Bouwman (Jumbo-Visma) 294
2. Giulio Ciccone (Trek-Segafredo) 163
3. Alessandro Covi (UAE Team Emirates) 102