Defending champion Colin Montgomerie made a steady start to his second round at the Caltex Masters in Singapore but it was fellow European Thomas Bjorn who turned up the pressure with a six-under-par 66.
After Thursday's bogey-free round of 65 Montgomerie blotted his copybook early by taking six at the 567-yard par-five second.
However, he bounced back immediately with birdies at the third and fourth, both par fours, to move to eight under for the tournament after seven holes - a lead of two over Bjorn.
The Dane, starting at the 10th after Thursday's level-par round, opened with two birdies and picked up three further shots between 14 and 16 before a three on the short par-four 18th sent him out in just 30.
Another birdie at the fourth briefly put him level with Montgomerie but he fell back again after bogeying the 193-yard fifth.
English duo Nick Dougherty and Mark Foster, joint second overnight on four under, both had birdies in their first three holes - on the back nine - as they sought to keep pace with Montgomerie.
The Scot's Ryder Cup team-mate Lee Westwood's indifferent form in his first tournament of the year continued as he carded a one-over-par 73 to leave him one under after 36 holes.
He began in impressive fashion with an eagle three on his second hole, the par-five 11th, but then dropped shots at the 17th and 18th to turn in 36.
The Worksop golfer then carded seven straight pars before an erratic finish brought a birdie two at the eighth and a double-bogey at the par-four ninth.
Another Ryder Cup winner, David Howell, also had an up and down start to his round with three birdies and two bogeys to remain one under after six holes.