England's Matthew Blackey was the surprise one-stroke leader of the Sao Paulo Open in Brazil yesterday in only his eighth European Tour event. The 28-year-old netted an eight-under-par 63 in the second round, breaking the course record set by first-round leader Paul Affleck by three strokes.

It took Blackey, a 1997 Walker Cup amateur, to nine-under-par 133, a stroke ahead of fellow Briton David Park, who shot 67, and two better than Spain's Thomas Munoz and Swede Per Nyman, who carded 68s.

Padraig Harrington added a three-under-par 68 to lie in joint ninth on five under par. But Philip Walton's woes continued as a two-over-par 73 left him outside the cut.

Blackey finished with a flourish, hitting birdies on the last two holes to make his birdie count eight with no dropped shots.

Only one of his birdie putts was not around the 15-foot mark, his chip to make four at the par-five 17th.

His surge to the top of the leaderboard so early in his career even took Blackey by surprise as he equalled his best score as an amateur and beat his best as a professional by a shot.

"It's quite strange looking up and seeing your name up on top," said the Englishman, who made this year's card from his third visit to tour school as a professional.

"But it's always what I wanted to do and it's where I've wanted to be. To do it after only eight events is quite something for me because I started the season concentrating on playing well enough to get reranked as high as I could and get more tournaments.

"This is only my fifth since making my card and my first three were a bit of trial. I came to Brazil for the two tournaments here knowing these two weeks are crucial because I don't have many more chances.

"I missed the cut by just a shot last week so I'm hoping this week is going to be a big one for me."

He and second-placed Park, great friends from amateur and Challenge Tour days, are rooming together this week.

"I guess there won't be too many tactics talked tonight," said Park. "It will be first one to get to sleep."