Toronto, Canada – Masters champion Angel Cabrera of Argentina eagled the par-five 18th on the way to an adventurous 66 to lie one stroke off the lead with nine other players.
The straight-hitting Johnson was delighted with his round, having shrugged off an early bogey at the par-four fifth with a flawless run of six birdies in the last 11 holes.
"It was good," the 2007 Masters champion told reporters after covering the back nine in a sizzling four-under 31. "I really played pretty solid all day.
"I made my short putts and hit some 15 to 30-footers really good. I just barely missed. My trajectory and control were the best parts of my game today.
WIND FACTOR
"The key element here is certainly the wind and the wind today was severe at times, especially early on in the round," added Johnson.
"This golf course incorporates everything for me -- high shots, low shots, working the ball a little bit."
Tour veteran Love, bidding for his first victory since the 2008 Disney Classic, and Palmer each birdied their final holes to jump into a share of the lead.
"I birdied the first two holes in the big wind this morning, and so I was off and running," said a smiling Love. "That was a great way to start 2010.
"I didn't have a five on the card until I got done -- at five under (par). I made two nice 10-footers after bunker shots to save par. Other than that, I scrambled around pretty good."
Merritt, who won last year's PGA Tour qualifying tournament, was the surprise package at the top of the leaderboard, recording six birdies and a lone bogey in his debut appearance on the U.S. circuit.
Twice winner Ernie Els and 2005 champion Vijay Singh, each making their first starts on the 2010 PGA Tour, opened with matching 69s.
(Writing by Mark Lamport-Stokes in Los Angeles; Editing by Nick Mulvenney)
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