Jordan Spieth hung on to his lead after the second round of The Masters, but it was trimmed to just one shot as Rory McIlroy closed in on the defending champion.
Spieth ended day one two clear of the rest and extended that lead to five shots at one point thanks to two early birdies on day two.
However, Augusta was playing extremely difficult and very few players broke par on Friday because of swirling winds and tricky pin positions.
McIlroy, who is seeking to complete the career Grand Slam by adding The Masters to his Open, US Open and US PGA titles, shot the joint-lowest round of the day with a one-under-par 71 that left him three-under for the tournament.
Spieth's hot start had him at eight-under, but he failed to hold his advantage on the back nine and will start round three just one ahead of playing partner McIlroy in a final group containing two of the world's top three players.
Spieth, who has now led after six straight rounds at Augusta, played alongside US Amateur champion Bryson DeChambeau in the first two rounds and the latter almost denied the Spieth-McIlroy pairing.
The youngster was three-under on the final hole but lost his ball with his first drive and eventually took a triple-bogey six to drop back to level par.
New Zealand's Danny Lee and American Scott Piercy are joint-third on two-under, and only three other players are under-par at -1 heading into the weekend.
The cut was seven-over and among those to be eliminated were former champions Phil Mickelson, Charl Schwartzel and Zach Johnson, with the latter dropping the below the cut-line because of a two-shot penalty he incurred for grounding his club in a hazard.
