|Arnold Palmer Invitational Second-round leaderboard|
|-13 Morgan Hoffmann (US), -10 Matt Every (US), Henrik Stenson (Swe), Harris English (US) -9 Ben Martin (US), -8 Danny Lee (NZ), Rory McIlroy (NI), David Lingmerth (Swe), Matt Jones (Aus), Selected: -7 Ian Poulter (Eng), -5 Padraig Harrington (Ire), -4 Martin Laird (Scot) -3 Danny Willett (Eng), -2 Russell Knox (Scot) Missed cut -1 Paul Casey, Even Graeme McDowell (NI)|
Rory McIlroy charged up the leaderboard at the Arnold Palmer Invitational after a second-round 66 but is still five shots behind leader Morgan Hoffmann.
The Northern Irishman's first-sub 70 round on this year's PGA Tour included a run of five birdies on his back nine.
Hoffmann added a 65 to his opening six-under 66, which left him on 13 under and three ahead of holder Matt Every, Henrik Stenson and Harris English.
McIlroy shares sixth with New Zealand's Danny Lee and Sweden's David Lingmerth.
Stenson, defending champion Every and English all fired rounds of 66 as they moved to 10 under while former US Amateur champion Lee shot a brilliant 64.
England's Ian Poulter is in a group on seven under while recent Honda Classic winner Padraig Harrington is sharing 23th spot on five under after a 71.
World number one McIlroy's compatriot Graeme McDowell missed the cut after a second 72 left him on level par while Paul Casey also exited on one under.
After starting at the 10th, McIlroy needed to save par from greenside bunkers three times to cover the back nine in 34 after birdies on the 10th and 16th.
However, the four-time major winner clicked into top gear after the turn, holing from 18 feet on the second, six feet on the third and seven feet on the fourth before a superb approach to the fifth left him just inches from the hole.
The 25-year-old then got up and down from another bunker on the par-five sixth for his fifth straight birdie.
McIlroy's only bogey came at the eighth after a miscued drive led to him finding more sand.
The world number one had dinner with tournament host Palmer on Thursday night and described the evening as "fantastic".
"It was just great to be in his presence, and great to be in his company," added McIlroy.
Leader Hoffmann's second round included nine birdies as he set a clubhouse target which never looked like being matched.
New Jersey-born Hoffmann, 25, started the event on Thursday after learning that his 97-year-old grandmother had died.