Couples shows the way again at Augusta

Fred Couples has mirrored his achievement of last year by setting a halfway target of 139, though he will hope that is where the comparison ends.

As damp and dreary conditions gave way to sunshine at Augusta National, the 1992 Masters champion improved to five under with a 71 to set the standard in the clubhouse. Last year, alongside Jason Dufner, he entered the weekend leading on the same score but carded a 75 on Saturday to drop out of the reckoning.

It was a very different story for Spain's Sergio Garcia, who fired a first-round 66, but went in reverse during the gloomy morning hours and posted four bogeys to drop back to two under with a 76. His compatriot Gonzalo Fernandez-Castano, who opened with a 68, also struggled as he mixed three birdies with five bogeys in a round of 74.

China's 14-year-old Guan Tianlang, who shot an impressive 73 on Thursday in becoming the youngest ever Masters competitor, fired a second-round 75 for a 36-hole total of four-over 148, putting him in contention to make the cut. However, his round was soured by the one-shot penalty for slow play, though he appeared anything but the sole offender.

"Yeah, I respect the decision they made," he told Sky Sports. "It was windy on 12 and I changed my mind in terms of the club. It (the warning) did affect me a little bit. On the 18th I did well to make par."

The Irish challenge was a mixed bag as Rory McIlroy desperately went in search of consistency. After dropping back to two over with early bogeys, he eagled the eighth to move back to level par and picked another two shots up at 13 and 14, before giving a one back at the par-three 16th.

Pádraig Harrington was nine over for the tournament after four holes, thanks to a bogey at the second and a double-bogey at the third. Graeme McDowell was two over through seven holes and one over for the tournament.

The big mover of the day was the 2009 Masters champion Angel Cabrera, who shot a 69 to move to four under, while Bernhard Langer improved to two under with a round of 70.

Dustin Johnson was at seven under after the 10th hole, but capitulated after that, dropping six shots in the last five holes to drop back to one under.

Overnight leader, Australian Marc Leishman remained on six under by the turn and was still on course to overtake Couples' 36 hole total, as might Jim Furyk, who was five under through 11, two under for his round.

Tournament favourite Tiger Woods moved to three under at the fifth.