Sabbatini made three late birdies to take control in Ohio

SECOND-ROUND LEADERBOARD:
US unless stated
-6 R Sabbatini (SA)
-4 Z Johnson
-2 K Perry, S Verplank, T Woods
-1 L Westwood (Eng), D Love, C DiMarco

Rory Sabbatini retained the lead in the second round of the WGC Bridgestone Invitational at Firestone with Zach Johnson and Tiger Woods close behind.

South African Sabbatini shot a second 67 to go six under, two clear of Masters champion Johnson who shot 65.

Tiger Woods stayed in touch with a 70 to remain on two under, alongside Scott Verplank and Kenny Perry.

Sabbatini's fellow overnight leaders Paul Casey and Hunter Mahan slipped back to level par with rounds of 73.

"There are not that many guys under par and the leader is by no means running away with it," said Casey.

606: DEBATE Who will win at Firestone?

"I'm even par and not completely out of this thing yet. If I get it going over the weekend, we will see what happens."

Lee Westwood slipped back a stroke with a 71 but remains in contention on one under in a group of five players.

Colin Montgomerie made a double bogey at the 14th to finish with a 72 and stand at three over, while Open champion Padraig Harrington made two late birdies to go to one over.

Phil Mickelson and Vijay Singh were locked at six over after returning 72s, one ahead of Ernie Els who struggled to a 77.

Sabbatini strung three birdies together on 15, 16 and 17 to go clear of the pack.

"It's a matter of picking and choosing your targets out there," said the 31-year-old South African.

"There are opportunities where you can be aggressive but you have to kind of back down and just give the course respect, otherwise it'll hit you pretty quickly."