The battle between Bernhard Langer and Mark Wiebe for the Senior British Open Championship will go into a fifth day after bad light brought an end to play following the second playoff hole at Royal Birkdale on Sunday.
The pair were locked at nine-under par after 72 holes after German Langer blew a two-shot lead on the final hole with a double bogey to send the championship into a playoff.
Play had earlier been held up twice due to rain and the threat of thunder and lightning.
Langer, who won the tournament in 2010 at Carnoustie, held a three-shot lead heading into the final day, and looked to have secured the title with another solid round.
American Wiebe, who shared the lead with Langer after the second day, hit a four-under-par 66 on the final round which was good enough for outright second until Langer's meltdown on the 18th.
The pair played two extra holes in near darkness before the decision was made around 2045 GMT to come back on Monday morning to resume the playoff.
America's Corey Pavin, Peter Senior of Australia and South Africa's David Frost were tied for third at six-under par.
(Reporting by Josh Reich; editing by Toby Davis)