Brazil’s Adilson da Silva nervously struck the first golf shot at the Games in 112 years while Rose did even better - and aced the fourth hole.
But Masters champion Willett had a tough back nine, dropping two shots to sit on level par, eight shots adrift of clubhouse leader Marcus Fraser. Fraser needed four Australian players to withdraw from the Games to seal his place in the team, with world number one Jason Day and former Masters winner Adam Scott among those dropping out.
But he seized his chance with a 63, which left him two shots ahead of Open champion Henrik Stenson and Canada’s Graham Delalet.
Rose’s ace left him in a five-way tie for fourth, four shots off the early pace.
Most Popular
-
1
Rivelin Valley Road Sheffield: Body found after police search of Rivelin Valley
-
2
The Long Blondes: Leadmill cancel gig after allegations surface against band creator Dorian Cox
-
3
Hosepipe ban: Reservoir near Sheffield less than 15 per cent full as photos show how water levels have plunged
-
4
Yorkshire Water announces hosepipe ban as Government prepares to declare drought in UK
-
5
Sheffield businessman Rong Ren ordered to pay £1.1m by courts over phones scam
Since winning at Augusta, Willett has struggled for form with a third place at the BMW PGA Championship at Wentworth his best performance.
He missed consecutive cuts on the Tour before tying for 53rd and 79th in his last two outings at the Open and PGA Championship.
“It’s one of those rounds that could have been a lot better,” he said. “It’s just the first round but I’ll need to find some putts and take some chances because it’ll need a low score somewhere to get back in the mix.”
The last time Rose bagged an hole in one he won a car but he insisted this was a much better claim to fame.
Rose rescued what was looking like a scrappy round.
“There is always an element of luck but you could chalk it up as a good hole-in-one. When you are the first to do something no one can take that away from you. That was definitely a cool moment - the first-ever hole-in-one at the Olympics will always be mine. It was one of those hole-in-ones that I was probably aiming just right of the pin and it was a lovely shot, landed on line and went in.
n Aldi is the first Official Supermarket partner of Team GB and has been championing our nation’s extraordinary athletes on their Road to Rio and encouraging the public to tuck into fresh, affordable, Great British food. For more information visit aldi.co.uk