Miami - Australia's Jason Day fired a bogey-free seven-under par 65 on Friday to take a two-shot lead over Henrik Stenson after two rounds of the Arnold Palmer Invitational at Bay Hill.
Last year's PGA Championship winner has his eyes firmly set on back-to-back major titles with the Masters looming in three weeks at Augusta National.
World number three Day birdied three par-5 holes and followed up his opening 66, which put him one stroke ahead when the round began, with another impressive round at the Orlando layout leaving him on 13-under 131 for 36 holes.
"It's great to be there," said Day, who led by five strokes when he finished his round. "Definitely way above average. I had it on a string around here the past two days. I'm very happy with the way I've gotten around this course."
Day, who began his round off the 10th tee, sank a two-foot birdie putt at the par-5 12th, tapped in for birdie at the par-5 16th after missing a 17-foot eagle bid and dropped a 37-foot birdie putt at the par-3 17th.
The Aussie dropped his approach inches from the cup to set up a birdie at the fourth, sank a 12-foot birdie putt at the fifth and added a three-footer for birdie at the par-5 sixth.
Then he closed out the round by banging in a 36-foot birdie putt at the ninth.
"My goal was to be patient out there but still aggressive with the lines I was taking," Day said.
"Today I hit some phenomenal drives to set up some great irons into the greens. Played the par-5s great and his a couple huge bombs out there."
Stenson was eight adrift when he teed off later in the day, but climbed up the leaderboard with a 66.
"It's motivating," Stenson said of starting so far back. "You can't let it be frustrating that you're eight shots back.
"He played great, and you've just got to go and do the same, and I managed to do that," added Stenson, who made five of his seven birdies on the back nine.
England's Justin Rose also signed for a 66 that left him three shots back on 134.
After a rollercoaster first round that included two eagles and a double-bogey, Rose was pleased to notch six birdies without a bogey.
"Yesterday was a colorful scorecard," Rose said. "Today, a little bit more solid."
Day, Stenson and Rose will tee off together on Saturday as organizers send the field off in threesomes from both the first and 10th tees in an effort to beat expected inclement weather.
131 - Jason Day (AUS) 66-65
133 - Henrik Stenson (SWE) 67-66
134 - Justin Rose (ENG) 68-66
136 - Jamie Lovemark 68-68, Troy Merritt 67-69, Kevin Chappell 68-68, Derek Fathauer 70-66
137 - Paul Casey (ENG) 68-69, Marc Leishman 67-70, Brendan Steele 67-70
138 - K.J. Choi (KOR) 68-70, Jason Kokrak 70-68, David Hearn (CAN) 71-67, Chris Wood 69-69, Rob Oppenheim 70-68