Colloquially known as the ‘Shark Shootout’ and an unofficial PGA Tour event, two-person teams played a scramble format in the opening round where both players tee off, select the best shot and then each play from that spot, following that format until the hole is complete.

An eagle at the par-5 17th capped a 15-under par round of 57 for the team of Graeme McDowell and Corey Conners to set the early pace at Tiburon Golf Club but the Aussies stormed home in spectacular fashion to assume the clubhouse lead at 16-under par.

Starting with birdies at both of their opening two holes, it was a stretch of five holes around the turn that Day and Leishman played in seven-under par that sent them soaring up the leaderboard.

Their run of red numbers began with a crafty pitch and run hole-out by Leishman from just short of the green at the par-5 sixth for eagle and following three straight birdies ended with a second Leishman hole-out at the par-4 10th, a flip wedge from 55 yards taking two hops and rolling gently into the cup for another two-shot boost.

“It really helps the score when you have a couple of shots go in that you don’t really expect,” Leishman said post-round.

Day credited the pair’s history at numerous Presidents Cup campaigns for the chemistry that catapulted them to the top of the leaderboard on day one.

“As teammates over multiple Presidents Cups we’ve got that comfort level and being from Australia we’ve been good mates for a long time,” said Day.

“I played amateur and junior golf with Leish so I’ve known him for a very long time and just the dynamic of how he hits the ball, I know he’s going to keep it out in front of him and I can try and get the ball down there as far as we can.

“Leish played some tremendous golf today. We talked about the two hole-outs but his putting is really crucial for us.”

After back-to-back pars at 11 and 12 the pair got on a roll again to close out their back nine, making six straight birdies from the 13th hole punctuated by another perfect putt for birdie by Day at the par-4 18th.

Their 12th birdie of the round for 56 was just one shot shy of the all-time QBE Shootout record of 55 set by Ryan Palmer and Harold Varner III in 2019.

It was a good day also for the only other Aussie in the field, Matt Jones.

Playing with Palmer, Jones is in a share of seventh five strokes off the lead, the pair combing for nine birdies and an eagle in a round of 11-under 61 after being five-under through their first four holes.

The Shootout moves to the more challenging foursomes alternate shot format for round two and then ends with the fourball best ball in the third and final round.