Virginia Water, England - Veteran Dane Thomas Bjorn crammed eight birdies and an eagle in a sizzling 10-under 62, producing the lowest score in relation to par in the history of the BMW PGA Championship.
The 43-year-old's timing was impeccable, as he finished his round just before a torrential downpour forced play to be suspended because of a threat of lightning.
Bjorn, 15-times a winner on the European Tour, matched the nine-under 62 recorded by Robert Karlsson in 2010 - but the Swede's effort came when the par for the West Course at Wentworth was 71.
The Dane, who did not drop a stroke all day, reached the turn in 32 with birdies at the second, fourth and seventh.
Early starter Bjorn then put his foot firmly on the gas on the homeward trek, adding an eagle three at the 12th to birdies at the 10th, 11th, 14th, 16th and 18th.
South African Justin Walters was in second place in the clubhouse on 67, one ahead of Englishman David Horsey.
World number 10 Rory McIlroy, who announced his split with fiancee Caroline Wozniacki on the eve of the European Tour's flagship event, was among the late starters. – Reuters