Ecuadorian Olympic road race champion Carapaz, racing for Ineos Grenadiers, had predicted that the final five kilometre climb to the stage 20 finish on the Marmolada at an average gradient of more than 11 per cent would be crucial to determining the outcome of this year's Giro.

The 2019 winner held the pink jersey since stage 14, with his lead standing at three seconds going into the penultimate stage.

He was neck-and-neck with Australian Hindley until approximately two kilometres remaining, but Hindley - assisted by Bora-Hansgrohe team-mate Lennard Kämna of Germany, who dropped back from a breakaway, launched an attack which sent him clear of Carapaz and on course to become the first Australian to win the Giro.

Hindley has taken a lead of 1min 25sec with only a 17.4 kilometres time trial in Verona left to navigate.

He went into the final day time trial with a narrow general classification advantage at the 2020 Giro, but had to settle for second place after being caught by Britain's Tao Geoghegan Hart.

The 168km five-star stage from Belluno to the Marmolada featured three tough climbs, and was won by Italian home favourite Alessandro Covi of UAE Team Emirates.

Covi's first Grand Tour stage victory came in 4hr 46min 34sec, which was 32 seconds clear of Slovenia's Domen Novak of Bahrain Victorious.

Another Italian rider in Trek-Segafredo's Giulio Ciccone rounded off the podium a further five seconds back.

Hindley came through in sixth for the stage, finishing 2min 30sec off the pace, with Carapaz coming through in 11^th in 4:50.32.

Spain's Mikel Landa of Bahrain Victorious placed ninth, finishing 3:19 behind Covi.

Landa is third overall, and all but assured of a place on the podium.

He trails Hindley by 1:51 and Carapaz by 26 seconds.