Englishman Ross Fisher and South African Tim Clark posted five-under-par 68s to equal the course record and move into the overnight lead at the South African Airways Open.
Swede Henrik Nystrom finished one behind the top spot, with compatriot Mattias Eliasson and South African Charl Schwartzel on three-under for joint third.
Teeing off on the back nine, defending champion Clark posted four birdies and an eagle for his round, the only blemish coming with a bogey on his final hole, the ninth.
Fisher teed off on the tenth hole and posted five birdies and four pars to draw level with Clark at the turn.
His back nine was not as consistent and he finished with two bogeys at the first and eighth, although he carded another two birdies at the fifth and ninth to go back to five-under.
"I've always been strong off the tee and that helped today," Wentworth member Clark explained.
"It gave me the chance to play for the correct side of the green - maybe 20 or 30 feet off-line - and let the ball feed in. Because of this, I was able to set my putts up nicely.
"Things were very slow at the beginning. It was hard to concentrate but I just told myself to just be patient and it was nice to end it with a birdie at the 18th."
Fisher's best result to date was a fourth at the European Tour's 2006 Volvo China Open, held last month.
He finished 18th on the 2005 Challenge Tour to secure his playing privileges for 2006 and then finished 14th on the European Tour Qualifying School to improve his category listing.
He started playing the game at the age of just three and turned professional in 2004.
Clark has officially joined the European Tour and will play at least the minimum 11 tournaments required during the 2006 season.
A victory on Sunday would cap a fine year for the South African, who celebrates his 30th birthday tomorrow. He picked up #1.3 million on the PGA Tour, won the Scottish Open, finished third in the US Open and rose more than 50 places on the world rankings.
South African-born Justin Rose carded a one-over-par 74 for joint eighth.
Rose explained: "I think my bogey on the first hole summed things up for me but I enjoyed grinding it out today.
"The back nine was much better and to finish anywhere near level par on day one is good. I'm looking forward to tomorrow."
Hill Valley's Jonathan Lomas led the Midlands interest but he was eight shots off the lead after his 76. The highlight in his round was an eagle three at the 13th, but his optimism had been dented by five bogeys between the second and tenth holes.
Lomas was one shot ahead of Birmingham's Sam Walker and two better than Tom Whitehouse. Walker included a double-bogey seven at the fifth but a birdie four on the 18th on a roller-coaster round, while Whitehouse, his cousin, mixed six pars, seven bogeys, one double-bogey and four birdies in his 78.
It was a day to forget, however, for John Bicker-ton, who carded a seven-over-par 80 with five birdies and one double-bogey, while Robert Rock struggled to an 82. One birdie at the third could not rescue his round after six bogeys and two double-bogeys.