London: Zach Johnson and Adam Scott both reached the turn at 14 under to co-lead by one in the final round of the weather-hit British Open at St Andrews on Monday.
The 2007 Masters champion had five birdies in the rain for a 31 as he leapfrogged others packed together at the top of the leaderboard.
Going down the front nine behind him, seven players were on 13 under - Adam Scott, Marc Leishman, Jordan Spieth, Padraig Harrington, Louis Oosthuizen, Jason Day and Sergio Garcia.
A shot further back came US amateur Jordan Niebrugge, who had moved above Irish amateur Paul Dunne, the co-leader overnight who fell back to 11 under with bogeys at the first two holes.
The 2013 Masters champion Scott then birdied the ninth to join Johnson in the lead at 14 under.