Ryan Fox shot a stunning 66 on the third day of the Soudal Open at Rinkven International Golf Course in Antwerp, Belgium, to edge overnight leader Sam Horsfield from the top of the leaderboard with 18 holes to play.
The New Zealander started his day with a bogey on the third, but countered with a birdie on the fifth.
Fox, 35, is seeking his second DP World Tour win of the season after claiming the Ras al Khaimah title in February.
The remainder of his front nine was unremarkable, but after the turn he picked up five shots to take the lead at 11-under.
Horsfield finished the round with a 69 to sit at 10-under, while Yannik Paul is a further stroke back at nine-under after carding a 68.