Ireland's Shane Lowry set the clubhouse target on a difficult second day of the Alfred Dunhill Links Championship on Friday.
Lowry added a round of 70 at St Andrews to his opening 66 at Kingsbarns to finish eight under par in the pro-am event, one shot ahead of Scotland's Chris Doak, whose 67 at Kingsbarns was one of the best scores in wet and windy conditions.
A birdie on his final hole ensured Lowry edged ahead of the pack on a crowded leaderboard, with Padraig Harrington, Oliver Wilson and Raphaël Jacquelin all seven under par alongside Doak.
Scotland's Stephen Gallacher, who made his Ryder Cup debut last week at Gleneagles, had also been seven under before a double bogey on the seventh at Kingsbarns, where European team-mates Rory McIlroy, Martin Kaymer and Victor Dubuisson were also in action.
McIlroy, partnered by his father Gerry and keen to make the cut in the team event so Gerry could play St Andrews on Sunday on his 55th birthday, started the day nine shots off the pace and dropped back to two over par with a bogey on the 14th.
However, the World Number One responded in style with a superb fairway-wood approach to the par five 16th and rolled in the eagle putt from 15 feet before making birdies on the 17th, first and third.
The 25 year old then drove the green on the short par four sixth to set up another birdie and move to four under par, just four behind Lowry and with a potential two more rounds at St Andrews to come.
McIlroy carded an opening 63 over the Old Course in the 2010 Open and has also finished second twice, third and eighth in five appearances in this event.
