Britain’s Sam Watson won the opening stage prologue of the Santos Tour Down Under for Ineos Grenadiers ahead of compatriot Ethan Vernon.

British road race champion Watson, 24, beat Vernon by just half a second on the 3.6km race against the clock in Adelaide, South Australia – the first race of the 10-month long UCI World Tour.

Watson said: “I’m so happy to start the season with a win. It’s amazing to be leading the race. It’s great for myself and the team to start the season like this.”

British high-budget team Ineos are looking to significantly improve performances this season after a staff and management reshuffle last year aimed at facilitating a return to the years where the team dominated the Tour de France.

In warm summer conditions riders competed on road bikes with rear disc wheels instead of time trial bikes, largely to reduce travel costs for a race thousands of miles from the sport’s European base.

Prologues are typically much shorter than time-trials and are often not the best indicator of form.

Vernon, 25, who rides for the new NSN cycling team co-owned by World Cup winner Andres Iniesta, is known for sprint finishes and could aim for victory on stage one.

The Tour Down Under runs for six days, with Saturday’s stage to Willunga Hill the toughest climbing test for the riders.

On Monday Britain’s Josie Nelson finished 12th overall for Picnic-PostNL in the women’s edition of the race having spent much of the three-day event in the blue points jersey.

Switzerland’s Noemi Ruegg won overall, defending her title from last year.