After two bogeys on the first three holes, the former Ryder Cup player had six birdies on the last 13 to finish at 7-under 206. He is trying to win the tournament for the third time in five years.
There must be something in the beer in Portugal, said Broadhurst, who had missed six of nine prior cuts this season.
Jamie Donaldson of Wales (67), Englands David Lynn (65) and Maarten Lafeber of the Netherlands (64) were one shot back at the Oitavos Dunes course.
Its not over until its over here. We saw that in 2005, said Broadhurst, who won the title that year after his rivals all faltered on the final few holes. Broadhurst also won the tournament in 2006.
Ross McGowan, who led by one after the second round, was tied with Broadhurst for the lead after 15, but missed birdies at the next two holes before bogeying the par-4 last. The Englishman finished with a 71 to sit two shots behind Broadhurst, same as Paul Lawrie (68) of Scotland.
A group of four other players were at 4 under at the $1.67 million European Tour event.