Lee Westwood and Brett Rumford shared the lead after the second round of the World Super 6 in Perth on Friday.

Defending champion Rumford held a two-stroke advantage after the opening day at Lake Karrinyup Country Club, but could only shoot an even-par 72 to remain on eight under.

He was joined on that mark by playing partner Westwood, who made four birdies and as many bogies, with an eagle at the par-five 15th the highlight of a mixed round.

Rumford picked up shots at the seventh and 11th but bogeyed 13 and 17. The pair will play together on Saturday - the last round of strokeplay before Sunday's matchplay - and the Australian says going up against a direct opponent will not affect his game.

"I'm happy to have signed for 72," said Rumford. "I'm happy to be tied for the lead and obviously happy that I'm in that top eight.

"You would have to lie to say that you're not aware of your opponent, but I'm not playing against [Westwood], I'm not changing my game plan or swing thoughts or nothing, I'm just playing golf."

"We both played well," added Westwood. "We haven't given too many shots away, made a few putts and I chipped in a couple of times. It's been fun over the first couple of days.

"I'm just trying to shoot as low as possible. I know if I carry on playing like I'm playing and a few putts start to go in, because I didn't really hole any putts today, I'll be thereabouts on the leaderboard.

"To be perfectly honest, matchplay is anybody's. You're going to need a lot of luck to win it."

Four men, including Thorbjorn Olesen, sit a shot behind the leading duo on seven under.