Justin Rose faltered after a flying start before bad weather forced play to be suspended in the third round of the 85th Masters.
Rose held a one-shot lead overnight and moved three clear with birdies on the first two holes at Augusta National, only to drop shots on the fourth and fifth.
The former US Open champion parred the sixth and had safely found the seventh green in regulation when the hooter sounded to call the players and spectators off the course due to an approaching thunderstorm.
At seven under par, Rose was a shot ahead of playing partner Will Zalatoris, with Justin Thomas, Corey Conners – who had a hole-in-one on the sixth – Hideki Matsuyama and Marc Leishman all on five under.
Former champion Jordan Spieth was a shot further back after following a double bogey on the seventh with a remarkable recovery from the trees on the eighth to set up an unlikely birdie.
Rose had earlier narrowly avoided a bunker with his opening drive and took full advantage, hitting his second shot to 12 feet and converting the birdie attempt.
The 40-year-old also birdied the par-five second, but bogeyed the fourth and fifth after failing to get up and down from a greenside bunker on both holes.
History was against Rose as he attempted to win his second major title, with only one of the last seven players to lead outright after each of the first two rounds going on to claim the green jacket.
That player was 2015 champion Spieth, the last man Rose will have wanted to see in his rear-view mirror thanks to the three-time major winner's brilliant record at Augusta.
The 27-year-old finished second on his debut in 2014, led from start to finish in 2015 – Rose was joint second with Phil Mickelson – and finished runner-up the following year after squandering a five-shot lead with nine holes to play.
In 2018, Spieth led after 18 holes for the third time in four years before almost snatching the green jacket away from Patrick Reed with a closing 64.
A loss of form saw the former world number one slump to 92nd in the rankings as recently as February, but Sunday's victory in the Valero Texas Open made him one of the pre-event favourites, a status he justified with rounds of 71 and 68 over the first two days.
With the wind forecast to pick up in late afternoon, the early starters had the chance to make a potentially significant move up the leaderboard, but the first group out of Ian Poulter and Paul Casey could only manage rounds of 72 and 73 respectively.
Poulter's four birdies were cancelled out by four bogeys, while Casey also carded four birdies but five bogeys, the last coming on the 18th after pushing his approach into a greenside bunker following an ideal drive.
Three-time winner Mickelson and former Open champion Francesco Molinari carded the best early scores, matching rounds of 69 leaving the pair on level par.