Reigning champion Jordan Spieth demonstrated some superb scrambling skills to extend his advantage at the Masters after nine holes of his third round, but Jason Day had climbed ominously up the leaderboard as the tournament remained wide open at a blustery Augusta.
For the second day in succession, gusting winds, which were forecast to ease later in the day, and glass-like greens ensured scoring was proving incredibly difficult.
Spieth, part of a mouth-watering final pairing with Rory McIlroy, was guilty of a number of loose shots, but nevertheless improved his position by turning in 35 - thanks largely to some typically strong work around the greens.
At five under, last year's wire-to-wire winner had pulled four clear of playing partner McIlroy, who was out in 36.
Japan's Hideki Matsuyama had emerged as the nearest rival to Spieth, reaching two under through 10 holes, while world number one Day was only one shot further back, alongside McIlroy and three others, following a sensational 69-foot birdie putt at the 14th.
Also at one under was Day's 58-year-old playing partner, two-time Masters champion Bernhard Langer, who matched the Australian with back-to-back birdies on 13 and 14. At two under for their third rounds, the duo represented the hottest pairing on the course.
Scott Piercy and Smylie Kaufman were the other players in red numbers and Dustin Johnson remained very much in contention at level par despite missing a host of chances around the turn.
Spieth's front-nine birdies came at the second and eighth, but the young Texan had to work hard just to make bogey at seven and held a number of clutch par putts.
McIlroy, seeking a career Grand Slam, also slipped up at seven courtesy of a three-putt, having earlier bogeyed the third.
The strength of the winds was illustrated by an unfortunate incident for Billy Horschel at the 15th. Horschel's ball blew off the front of the green and into a water hazard before he had chance to mark it, leaving the American, who went on to card an impressive 73, to curse his ill fortune.
With only a handful of players in red figures, Lee Westwood and Louis Oosthuizen could be delighted with rounds of 71, which left them one and four over respectively.