Scott is closing in on the number one ranking held by Tiger Woods, who is not playing at Bay Hill this week due to injury.
And the reigning Masters champion is perfectly positioned to secure the 11th PGA Tour title of his career after following up his course-record-equalling opening round of 62 with a 68 on Friday.
If the 33-year-old maintains his form over the next two days, he would become the first Australian since Rod Pampling in 2006 to win the event.
At 14 under after his four-under 68, Scott holds a healthy advantage over Americans Chesson Hadley (68) and JB Holmes (69) and Italian Francesco Molinari (70), who share second spot.
American Keegan Bradley was one of the day's biggest movers, climbing 35 spots to a share of fifth on the back of his round of 67.
Keegan, winner of the 2011 PGA Championship, holed six birdies to sit at six under alongside compatriots Jason Kokrak, Brandt Snedeker and Morgan Hoffmann, and Welshman Jamie Donaldson, who all posted rounds of 71.
Ryo Ishikawa and John Merrick had been Scott's closest challengers at seven under after day one, but both men carded 74s in their second rounds to drop down the leaderboard.
Freddie Jacobson (68), Matt Every (70), Ian Poulter (71) and Charles Howell III (71) were also nine shots off the pace at the halfway mark.
Irishman Padraig Harrington (70) headlined a group of eight players at four under, including the likes of American Erik Compton (68), Australia’s Aaron Baddeley (70) and South Korean Seung-Yul Noh (68).