Hoylake - South African George Coetzee stormed up the British Open leaderboard on Friday morning, as the second round got underway in fine but breezy weather.
Playing in his fourth Open, the 27-year-old from Pretoria dropped a stroke at Royal Liverpool's second, but he responded with five birdies to get to a lead-sharing six under after 15 holes.
Bogeys at the 16th and 17th halted his progress, but he birdied the par-five last for a 69 and a total of five under, one shy of the lead.
That was held by Rory McIlroy, who had a mid-afternoon tee-off time, having enjoyed an overnight one stroke lead over Italy's Matteo Manassero with seven players on four under 68.
These included Italian brothers Francesco and Edoardo Molinari, Americans Brooks Koepka and Jim Furyk, Sergio Garcia of Spain, Ireland's Shane Lowry and world number one Adam Scott.
The Australian had a nightmare start to his second round with two missed short putts at the second and third to fall to two under.
But he pulled one back at the fifth and was three under through seven holes.
Thai veteran Thongchai Jaidee also moved up the leaderboard with three birdies to get to three under after 11 holes as did Spain's Rafael Cabrera-Bello who was on the same mark after four holes.
Defending champion Phil Mickelson reached the turn at one over after picking up a stroke, while top home hope Justin Rose was at two under after a long birdie putt at nine before chipping in from the fringe at the next.