A birdie on the ninth and a chip-in birdie on the 12th pushed him into the mix and, although he dropped a shot on 14 following a tee shot into the trees, the 36-year-old countered with back-to-back birdies to hit top spot.
Earlier, Rose birdied five of his last 11 holes to be the first in the clubhouse at four-under.
Scott started poorly with a three-putt bogey from 44 feet on the second hole and, although he made an eight-foot birdie on the fourth, trouble came on the next two holes.
The Queenslander pulled his approach shot on the fifth into the bunker and couldn't get up and down for par and then his tee shot on the water protected par three sixth went swimming.
He reduced the damage by pitching close from the drop zone and making bogey but looked anything but a contender at two-over.
But rather than slip into obscurity Scott kick-started his round by drilling a 19-foot birdie in on the eighth and then chipped in from the front of the 10th green to be back even on the day.
Back-to-back birdies on the 14th and 15th holes, the first from seven feet and the next a tap in after a missed 11 foot eagle try, ensured the 32-year-old still has hope of claiming a first win of the year.
"I played really lovely apart from a couple of swings on the front," Scott said.
"I was playing fine, but obviously five and six are tough, and I made a couple bad swings and made bogies.
"But I figured I'm playing fine and I'd get my opportunities, so I got back to hitting fairways and greens and had a few chances which was nice."
John Senden, the only other Australian in the field, wasn't at his ball-striking best and struggled to a two-over-par 72 to be tied 26th in the 30-man field.
Senden was one-under-par through seven holes but bogeyed three of his next five to fall off the pace.
"I just didn't play well today. I was a bit scattered on the back nine and made some crap bogeys around the turn," Senden said.
"I wasn't feeling as good as I wanted so I need to come back fresh tomorrow and go after it."
-AAP
