Grant Waite, Brian Bateman, Frank Lickliter, Jeff Maggert and Brian Gay are tied for third at 5-under-par 67.
Pride jumped out of the gate quickly. He started on the front nine of the Omni Tucson National Golf Resort and Spa and birdied the first three holes.
Pride, went on to birdie the fifth to move to 4-under. He later drained a birdie putt at the ninth hole to make the turn at minus-5.
Around the turn, Pride ran into trouble at the par-4 11th. He bogeyed that hole, but responded with a birdie at the next. Pride carded consecutive birdies starting with a 45-footer at the 14th to get to 7-under.
'My putting was phenomenal today,' said Pride, who is in the tournament thanks to a sponsor's exemption. 'I rolled the ball great. I didn't make every putt I looked at, but I made a lot of them.'
Pride, who won the FedEx St. Jude Classic nine years ago, is nearly fully recovered from gall stones and pancreatitis that threatened his life last season.
'It's just delightful,' said Pride, whose last tournament before getting sick was this event last year. 'It really is. I mean, just the whole year I'm trying to feed off the positive things that have happened to me, and I've been playing well.'
Baddeley had a rough start to his round. He birdied the 10th, his first hole, but gave that stroke right back with a bogey at the next. The Nationwide Tour alum carded a birdie at the 13th before moving to 3-under with an eagle at the par-5 15th. Baddeley gave a stroke back at the 18th with another bogey.
On the front side, Baddeley began a run of three straight birdies at the second. He later birdied the par-4 sixth to get to minus-6. Baddeley made a tremendous up-and-down, as he nearly holed his chip shot, to save par at the last to finish alone in second place.
'I hope it stays windy,' said Baddeley, referring to the weather that the afternoon groups fought through. 'Because if it stays wet, windy and cold, a lot of guys don't like it. I like it.'
Andrew Magee, Geoff Ogilvy, Rory Sabbatini, Dean Wilson, Jeff Brehaut, Dan Forsman, Kent Jones and Kenichi Kuboya are tied for eighth place at 4-under-par 68.
Defending champion Ian Leggatt was a late scratch as he aggravated an elbow injury while practicing on Wednesday.
Paul Gow, Ted Purdy and Scott Laycock are the three players who have not finished, and all three are over-par in their respective rounds.