Broadhurst finished the day one shot ahead of Denmark's Anders Sorensen and two in front of a group that contains the hobbling Jose-Maria Olazabal.
Emmanuel Dussart had an 11 at the 437-yard fourth, which included a two- shot penalty for stepping down the rough behind his ball, while his fellow Frenchman Michel Besanceney had a 10 at the long ninth. Another Briton Keith Waters carded a 10 on the 421-yard 15th, a hole where the green is almost an island and where the 147-strong field were a collective 142 over par.
Broadhurst was in the lake both there and at the ninth, but got away with bogeys each time and would have had a two-stroke lead but for taking three-putts at the 17th. Olazabal came home in 33 to show again that the small tumour he has on his right foot affects his walking more than it does his playing. Alongside him in joint third place are Nottinghamshire's Liam White, Adam Hunter of Glasgow, Sweden's Pierre Fulke and the 1993 winner, Costantino Rocca.
The defending champion, Mark Roe, the top European in last week's US Open, managed only a 76, while Sunday's Jersey Open winner, Andrew Oldcorn, shot the same score before withdrawing with a bad back.
The Australian Open champion, Robert Allenby, completed an unhappy fortnight by being disqualified after signing for a wrong score. Last week he was first reserve at Shinnecock Hills, but did not manage to play in th event.
Results, Sporting Digest, page 31Reuse content