LAS VEGAS, Nevada, Oct 10 - Experienced Americans Fred Couples and Tom Lehman both fired sparkling nine-under-par 63s to share the lead after the first round of the $4.5 million, 90-hole Las Vegas Classic Wednesday.

Three different courses are being used in this week’s tournament and while Couples was feasting on the 7,247-yard Southern Highlands Golf Club, Lehman was putting together his 63 on the TPC host course at Summerlin.

One stroke off the lead on 64 were Australian Craig Parry, South African Rory Sabbatini and American pair Joe Ogilvie and Tom Pernice Jr. Two shots back were left-hander Steve Flesch, Jim Carter and Bob Estes.

The two joint leaders are both using new equipment this week. Couples, 42, wielding a new putter with a shaft that rests on his stomach, played his best golf of the year in a round containing no bogeys, nine birdies and only 28 putts.

Lehman, 42, is using the second-generation Pro V1 ball by Titleist, which has a softer cover and better fits his lower ball flight.

The former British Open champion’s 63 was his best round of the year and two shots better than his third-round 65 at the Sony Open in Hawaii where he was second, his best finish of the year.

Couples has played in 17 events this year, making the cut 12 times but not finishing higher than joint 11th.

The former U.S. Masters champion has struggled on the greens this year, with a putting average ranked 114th on the U.S. PGA Tour.

Couples is without a victory since 1998 when he won twice — the Memorial and the Bob Hope Chrysler Classic, an event similar to Las Vegas in that it is played with amateurs and on more than one course.

This week’s competition features a professional and three amateurs in each group for the first three days.

Lehman has been away from tournament golf since he missed the cut at the U.S. PGA Championship seven weeks ago. He has also had to deal with the loss of his fourth child, a boy who was stillborn in July.

On Friday, Couples will play the par-71 TPC at the Canyons course, arguably the hardest of the three layouts. Lehman will go to Southern Highlands, seemingly the easiest of the three.

Leading first round scores:

63 Fred Couples, Tom Lehman

64 Craig Perry (Australia), Rory Sabbatini (South Africa), Joe Ogilvie, Tom Pernice Jr

65 Steve Flesch, Jim Carter, Bob Estes

66 Charles Howell III, Rich Beem, Robert Allenby (Australia), Jason Gore, Skip Kendall

67 Scott Verplank, Robert Damron, Russ Cochran, Pete Jordan, Greg Chalmers (Australia), Robin Freeman, Glen Day, Cameron Beckman, Andrew Magee, Kent Jones, Brian Gay, Shigeki Maruyama (Japan), John Daly

68 Andrew McLardy (Zimbabwe), Ian Leggatt (Canada), Fulton Allem (South Africa)

68 Stephen Ames (Trinidad and Tobago), 69 Jose Coceres (Argentina), David Frost (South Africa), Jesper Parnevik (Sweden), David Morland IV (Canada)

70 Stuart Appleby (Australia), Grant Waite (New Zealand)

71 Kaname Yokoo (Japan), Gabriel Hjertstedt (Sweden), 72 Paul Gow (Australia),

72 Per-Ulrik Johansson (Sweden), Stephen Allan (Australia)

74 Bradley Hughes (Australia), Craig Perks (New Zealand)

74 Ben Ferguson (Australia), 75 Geoff Ogilvy (Australia), Mathew Goggin (Australia)

77 Richie Coughlan (Ireland).—Reuters