The 18-year-old improved on a fourth place finish last year in the 500 metres time trial and added to her victory yesterday in the individual sprint.

She produced a blistering world junior record time of 33.937 seconds at the Velodrome Fassa Bortolo in the Italian town.

Lea Friedrich of Germany took silver in 34.301.

Bronze went to Yana Tyshenko of Russia in 34.625.

Britain's Lauren Bate had to settle for fourth today, in 34.907, after her silver medal in the sprint.

Gros repeated the double she secured on the same track at the 2016 European Championships.

It came on the penultimate day of competition at the flagship event for junior riders. 

A second world record followed in the individual pursuit first round as New Zealander Ellesse Andrews clocked 2:18.080.

Andrews, who won the team sprint last year before shifting to the endurance ranks, later won the final in a slightly slower 2:19.038.

Italy's Letizia Paternoster took silver in 2:19.641 while team-mate Elena Pirrone won bronze in 2:21.667.

Julius Johansen of Denmark also claimed victory today in the men's omnium.

He finished on a winning haul of 117 points.

Australia's Stephen Cuff took silver, on 109, and Uladzislau Tsimoshyk of Belarus the bronze, with 97.