THOUSAND OAKS (California), Dec 14: Mark O’Meara and Fred Couples both shot opening rounds of six-under 66 to share the lead at the $4.1 million Williams World Challenge Thursday, with tournament host Tiger Woods lurking just two shots back.

Joining Woods at four-under-par 68 were Vijay Singh and Scott Verplank.

Couples and O’Meara, one of Woods’s best friends in golf, won special invitations from Woods to the unofficial event and played side-by-side in the tournament that brings together 18 of the world’s top players.

O’Meara and Couples, a pair of former Masters champions, have both slipped in recent years and did not gain entry into the Sherwood Country Club field based on their world ranking.

O’Meara, who claimed a Masters/British Open double in 1998, is without a victory in three years and has dropped to 153rd in the rankings.

On Thursday, he showed signs of his top form as he took his score to seven-under until a bogey at 17 dropped him into a tie for the lead.

The 100th-ranked Couples, who also has not won since 1998, fired a 31 on the homeward half and finished his 66 by sinking a 30-foot par putt at the 18th.

Woods, who has shaved off his latest attempt at growing a goatee, birdied six of his first 12 holes, but struggled by pulling his tee shots and approaches.

Woods, last year’s runner-up, played the first round with defending champion Davis Love III, who posted a 71.

First round scores (US unless stated):

66 Mark O’Meara, Fred Couples

68 Vijay Singh (Fiji), Tiger Woods, Scott Verplank

69 Bernhard Langer (Germany), Padraig Harrington (Ireland)

70 Scott Hoch

71 Davis Love III, David Toms, Lee Westwood (Britain)

72 Darren Clarke (Britain), David Duval

73 Colin Montgomerie (Britain), Jesper Parnevik (Sweden), Thomas Bjorn (Denmark)

74 Mark Calcavecchia, Jim Furyk.—Reuters