AUGUSTA, GEORGIA (REUTERS) - Dustin Johnson will begin his title defence at the Masters at 10.30am ET on Thursday (10.30pm Singapore time) in a group with former runner-up Lee Westwood and amateur Tyler Strafaci.

World No. 1 Johnson, whose 20-under total last November at Augusta National Golf Club broke the Masters record shared by Tiger Woods and Jordan Spieth, will be in the 13th group to set off at the 445-yard, par-four first hole.

Following Johnson's threesome will be Xander Schauffele, world No. 3 Jon Rahm and Northern Irishman Rory McIlroy, who with a win this week would complete the career Grand Slam of golf's four majors.

Former champion Jordan Spieth, who rocketed into this year's Masters conversation after last week's Texas Open triumph, will go out in the last group at 2:00 p.m. ET with Australian Cameron Smith and former PGA Championship winner Collin Morikawa.

The penultimate group will feature world No. 2 Justin Thomas, who finished fourth at last year's Masters, world No. 13 Tony Finau and 2010 British Open champion Louis Oosthuizen.

Three-time Masters winner Phil Mickelson will tee off at 1.12pm ET alongside Tommy Fleetwood and Scottie Scheffler.

Other notable groups include reigning US Open champion Bryson DeChambeau, 2013 Masters winner Adam Scott and Max Homa.

Unlike last year's Masters, when split tees were used because of reduced daylight in November, all groupings will begin at the first hole.