Points fired a 7-under 65 and Imada had a 68, both scores shot over the Torrey Pines South Course. That left them tied at the top with two-day totals of 11-under 133.
Michael Sim shot the tournament's low round, a 62 on the North Course, and shared third place with Matt Every at 135.
Mickelson, playing for the first time this season, posted a 67 Friday and moved within four shots of the lead. His score, however, was not the focus of attention.
Changes in PGA Tour rules this year have forced players to use wedges that have a different width groove than the clubs that have been used in the past. The PGA, however, has made an exception of wedges made by Ping during the 1980s.
Mickelson and other players have put some of the old clubs into play but tour regular Scott McCarron has complained. In Friday's San Francisco Chronicle, McCarron accused Mickelson of "cheating" for using the Ping wedge.
"I think what he's saying is the rule is a terrible rule," Mickelson said after his round Friday. "I agree the rule is ridiculous. This kind of loophole is nuts. I don't agree with the way he's (McCarron) carried on about it, but that's his choice."
George McNeill, John Rollins, Ben Crane, Robert Allenby and Chris Tidland were tied for fifth place at 136.