Brooks Koepka is in contention for a remarkable fourth major title in his last seven starts after carding a flawless opening 66 in the 83rd Masters.Koepka was the only player not to card a single bogey on day one at Augusta National, but was denied the outright lead by a stunning finish from compatriot Bryson DeChambeau.DeChambeau birdied the 15th, was inches away from a hole-in-one on the 16th, chipped in on the 17th and hit the pin from 196 yards on the last to match Koepka’s six-under-par total.Seeking to become the oldest major champion ever, 48-year-old Phil Mickelson was a shot off the lead following a 67, with Ian Poulter and Dustin Johnson a shot further back and Tiger Woods four off the pace on two under.

TWEET OF THE DAY

Journalist Scott Michaux pointed out the significance of a possible Koepka victory, writing: “If @BKoepka goes on to win #TheMasters , every major will tee off with players seeking to complete career slams: #PGA (@JordanSpieth), #USOpen (@PhilMickelson), #TheOpen (Koepka) and #Masters (@McIlroyRory). Im not sure that’s ever happened before.”

SHOT OF THE DAY

From almost 200 yards, Bryson DeChambeau hit the pin on the 18th to set up a tap-in birdie for a share of the lead.

ROUND OF THE DAY

Koepka and DeChambeau both shot 66, but Koepka did so in almost effortless fashion and kept a bogey off his card despite some testing conditions and pin positions. The only blemish was a three-putt for par on the eighth.

QUOTE OF THE DAY

“I’m too big to play golf, and then when I lose weight, I’m too small. I’m gonna do what makes me happy. Seems to be working.”

Koepka responds to criticism of his recent weight loss.

STATISTIC OF THE DAY

The last 13 Masters champions have all been inside the top 10 after round one. Tiger Woods is tied for 11th and Rory McIlroy joint 44th.

TOUGHEST HOLE

The 18th was ranked the toughest hole with just five birdies, 28 bogeys and four double bogeys from the 87-man field leading to a scoring average of 4.356.

EASIEST HOLE

The 13th was unsurprisingly the easiest hole, the 510-yard par-five offering up three eagles and 43 birdies for a scoring average of 4.575, although Henrik Stenson did manage to rack up a triple-bogey eight.

ON THE UP

Sales of a Brooks Koepka diet plan after the joint leader’s recent weight loss, which has been heavily criticised in some quarters, did not prevent him shooting an opening 66.

ON THE SLIDE

Rory McIlroy’s chances of completing the career grand slam after an opening 73 left him seven shots off the pace.