With 54 kilometres left on the final mountain stage of the Giro d'Italia it was a combination attack by Team DSM and Bahrain Victorious that had race leader Egan Bernal and his INEOS Grenadiers teammates on the back foot.
Bardet had a pair of Australians in Chris Hamilton and Michael Storer leading the way for Team DSM, while for Caruso it was Pello Bilbao who was called upon to do the domestique work. The quintet caught the early breakaway of the day and began to drive the pace with Chris Hamilton in particular burying himself on the front as INEOS reformed behind, with super domestique Dani Martinez struggling a bit on the downhills.
The chase limited the gains of the second-placed rider on the general classification, with Caruso starting the stage two minutes and 29 seconds down on the race lead of Bernal. They reached a lead of 45 seconds, with Storer and Bilbao taking over what Hamilton had started and driving the pace hard.
The original breakaway and domestiques dropped off one by one from the front of the race until it was just the general classification pair of Caruso and Bardet left on the final climb of the Alpe Motta, with Caruso giving Bilbao a pat on the back for a job well done with just over six kilometres left before heading off up the climb with Bardet in tow.
The Italian was given no help by the Frenchman as he set a consistent pace on the climb, going head to head with Martinez, who showed why the INEOS squad had waited for him as he flew up the climb at the head of the main bunch, dropping all of the other riders fighting for their general classification.
Caruso hung tough, dropping Bardet with two kilometres remaining to solo away for the victory, but Martinez's work had halved his lead and Bernal was able to push clear in the final kilometres and cross the line for second place on the day, 24 seconds down on his nearest rival. The Colombian will go into the final stage time trial in Milan with just under two minutes advantage as the outstanding favourite to win the race overall.
Meanwhile for Caruso, it was a rare win for the 33-year-old Italian, he doesn't have the sort of explosive ability that allows him to take many wins, but the hard, gruelling nature of the stage played into the veteran's hands.
"I thought about a thousand things in the last metres before the finish line, all my sacrifices, my training, and all the work done by my teammates," said Caruso. "We rode in an exemplary way today, Pello Bilbao in particular did an incredible job and he played a fundamental role in this victory. Today I realised a dream, I think I am the happiest man in the world!"
Bernal has all but assured victory in Milan - barring serious misadventure - but still wasn't taking anything for granted ahead of confirming a second Grand Tour victory after his 2019 Tour de France win.
"I am satisfied with the result," said Bernal at the finish. "I think we managed the situation well. We have two minutes of an advantage for tomorrow's time trial, so I think we're in a good position."
"It's not the best to have the second on GC in front of you by almost one minute, but, still having three teammates, I tried to use them, and arrive as fresh as possible at the last climb."
The Giro d'Italia will conclude with the Stage 21 time trial in Milan, a 30.3-kilometre flat course that see the overall winner of the Italian Grand Tour crowned. You can watch all the action from 2115 AEST on SBS OnDemand, with SBS VICELAND coverage starting from 2120.
