LOS ANGELES, 20 Feb 2015, (AFP) - The two veterans were early pace-setters in the first round of the $6.7 million US PGA Tour event and finished the day in a six-way tie for the lead on five-under-par 66.
Singh nabbed six birdies with one bogey while playing partner Goosen had three of his seven birdies in the last six holes on the par-71 Riviera course.
They were joined on five-under by Korean-born American James Hahn, Nick Watney, Daniel Summerhays and Derek Fathauer.
Mexico's Carlos Ortiz was alone in seventh on four-under 67, with Germany's Alex Cejka, Australian Geoff Ogilvy and Americans Justin Thomas and William McGirt a further stroke back on 68.
Singh, who will celebrate his 52nd birthday on Sunday, spent 32 straight weeks atop the world rankings in 2004 and 2005 but hasn't won since 2008.
"I kept my ball in play, hit a lot of fairways, hit a lot of greens and when I did miss, I chipped it real close," the big Fijian said.
Singh, who has begun to scatter a few events on the Champions Tour for over-50s on his schedule, has battled a string of health problems and admitted it was good to play without pain.
"I'm finally not hurting as much as I did the last five years," the three-time major winner said. "That's a big part of playing good golf. You're not hurting, you can go out and play and you're comfortable."
Goosen's last victory on the US tour was at the 2009 Transitions Championship. The two-time US Open winner has struggled to find full fitness since back surgery in 2012.
"It was nice to play with Vijay," the 46-year-old South African said. "He played very solid too, and he putted really good. It's nice that the two old boys played so well. We were sort of feeding off each other."
As morning clouds burned off, the course firmed up, and Fathauer, a graduate of the Web.com tour, was the only late starter to challenge the leading group.
He got to five-under with his sixth birdie of the day on his 12th hole -- the par-four third.
But the 29-year-old, who played on the PGA Tour in 2009 after coming through Q-school but couldn't retain his card, was unable to find another birdie in the next six holes.
Nevertheless he was happy to find himself in the leading group.
"I just made some good saves, those three-, four-footers that you've got to make out here," he said.
Masters champion Bubba Watson, who won last year's Northern Trust Open, battled his way to a one-under 70 that left him in a group of 16 players.
A poor swing cost him a bogey from the trees at the par-four fifth, one of two bogeys against three birdies on the day.
"Didn't hit many greens," said Watson, the highest-ranked player in the field at number three in the world. "The swing wasn't feeling the best but somehow we kept getting up and down. I was missing in the right spots."
Leading first-round scores on Thursday in the $6.7 million US PGA Tour Northern Trust Open (Darkness halted play with three players to finish on Friday. USA unless noted, par-71):
66 - Retief Goosen (RSA), Vijay Singh (FIJ), Nick Watney, James Hahn, Daniel Summerhays, Derek Fathauer
67 - Carlos Ortiz (MEX)
68 - Justin Thomas, Alex Cejka (GER), Geoff Ogilvy (AUS), William McGirt
69 - Pat Perez, Jordan Spieth, Brendon Todd, Morgan Hoffmann, Ryan Moore
70 - Graham DeLaet (CAN), K.J. Choi (KOR), Hideki Matsuyama (JPN), Scott Stallings, J.B. Holmes, Michael Putnam, Paul Casey (ENG), Tony Finau, Alex Prugh, Danny Lee (NZL), Padraig Harrington (IRL), Angel Cabrera (ARG), Bubba Watson, Dustin Johnson, Matt Every, Matt Jones (AUS)