Goosen added only two birdies over the final 15 holes but had only one bogey en route to a 4-under-par 66 in a challenging breeze which gusted to 20 miles per hour on the Waialae Country Club course.
"A 66 today is probably as good as a 64 yesterday," said Goosen, whose 10-under 130 total was matched by Baddeley in the last group of the day.
Baddeley, a 21-year-old Australian phenom, finished strongly with three birdies on the final five holes for a 64, the day's best score.
Playing in the same threesome with his good friend Els, Goosen nearly drove it out of bounds at the par-5 ninth and had to settle for par on the easiest hole on the course. But that was about as bad as it got for the 2001 U.S. Open champion.
"I'm happy with the round," he said. "Overall, that's about as good as I could have done. I'm hitting the ball quite nicely at the moment and there were some really tough holes out there."
Despite sharing the lead, Goosen predicted Els would be the man to beat come Sunday.
"Ernie is hitting the ball a bit better than me but I've holed a few more putts," Goosen said. "If he gets the putter going, he's probably going to be the guy to beat on the weekend."
Els, who won last week's season-opening Mercedes Championship with a PGA Tour-record 31-under-par, sounded pleased with his form. He shot a 65.
"I missed quite a few opportunities, but you've got to be satisfied with 4-under and 5-under your first two rounds," he said. "Yesterday was a little scrappy, but today I hit the ball pretty crisply. The greens are putting beautifully, so a low score can be had."
DiMarco, meanwhile, was a little rusty last week but seems to have played himself into form, shooting a 66.
"I didn't finish last year until Dec. 9 and then I took a good 2 1/2 weeks off, so the preparation wasn't quite as good and it showed last week," DiMarco said. "I had a lot of rust."
DiMarco said his strategy this week was to "survive" the front nine.
"There aren't many birdie holes on the front nine," he said. "You just try to get to nine and make a charge from there and that's what a lot of guys are doing. I was able to do that today. I was even through eight and played the last 10 in 4-under."