SOUTHPORT, England — Henrik Stenson will begin defense of his British Open title alongside reigning Players champion Si Woo Kim and two-time major champion Jordan Spieth when the 146th edition of the oldest championship in golf begins Thursday at Royal Birkdale.

The three begin play at 9:47 a.m. local time (4:47 a.m. ET).

Hitting the first tee shot of the tournament at 6:35 a.m. local time will be Mark O’Meara, who won the Open here in 1998.

Padraig Harrington, who won in 2008 when the Open was last played at Birkdale, is off with Pat Perez and Thomas Pieters (4:36 a.m. ET). Reigning U.S. Open champion Brooks Koepka, who hasn’t played since he torched Erin Hills in Wisconsin to win the national championship, is playing with Hideki Matsuyama, who tied for second in the U.S. Open, and Tommy Fleetwood, who finished fourth at Erin Hills (5:09 a.m. ET).

Sergio Garcia, who won his first major at the Masters in April, is off with 2015 PGA champ Jason Day and Zach Johnson, who won the British Open at St. Andrews in 2015 (8:04 p.m. ET).

Rory McIlroy, who has missed the cut in three of his last four starts, is off with world No. 1 Dustin Johnson and 2011 Masters champion Charl Schwartzel (9:48 a.m. ET).

Jon Rahm, who won the Irish Open in his last start, is grouped with Patrick Reed and Lee Westwood (9:59 a.m. ET). Phil Mickelson, who hasn’t won since capturing the British Open in 2013 and was runner-up in the championship last year, is playing with Francesco Molinari and Marc Leishman (10:10 a.m. ET).

All times local

6:35 a.m. — Mark O’Meara,  Chris Wood,  Ryan Moore

6:46 —  Phachara Khongwatmai,  Maverick McNealy (a),  Stuart Manley

6:57 — Stewart Cink, Sandy Lyle, Jeunghun Wang

7:08 — Paul Broadhurst,  Thongchai Jaidee, Roberto Castro

7:19 —  Tom Lehman, Byeong Hun An,  Darren Fichardt

7:30 — Soren…