George Coetzee birdied four of his last six holes to share the lead at 10-under with overnight leader Henrik Stenson at the BMW International.
Stenson, who has not won since the Players Championship in Sawgrass in 2009, began at the 10th and eagled the sixth for the second day in succession.
But he bogeyed his final two holes to join Coetzee one ahead at halfway.
World number three Martin Kaymer had four consecutive birdies in a 68 and is four shots back in a tie for 15th.
The German narrowly missed an eagle putt on the 18th green but remained optimistic he could challenge in front of his home supporters.
"I am only four shots behind, which is not a lot on a course like this which offers plenty of birdies," the 26-year-old said. "I love playing with so many spectators and maybe on Sunday, we can win this together."
Coetzee, 24, is also in confident mood as he seeks a maiden European title.
"I have led a couple of times, but I'd like to finish first sooner or later," he said. "I think it's just a matter of trying to be in contention come the final afternoon. I don't really mind if I'm leading or not leading, just as long as I am within touching distance."
Despite his expensive finish, Stenson revealed even loftier ambitions.
"Let's try and have a good weekend here first, and then we have the British Open coming up in a couple of weeks. If I can keep on building on this progress, hopefully I can give myself some chances to win majors," said the Swede.
One man feeling rather less buoyant was Spaniard Sergio Garcia, who angrily dug his iron club deep into the fairway turf after a wayward approach and dropped three shots on his front nine having started at the 10th, before recovering to post a 71, which left him six shots behind the leaders.
The cut fell at two under, so Colin Montgomerie made it with nothing to spare the day after his 48th birthday, but Paul Casey missed by three after a 73, despite a closing eagle.
Another to fail to qualify was Nick Dougherty, who made his 15th successive early exit stretching back to last November.
However, Matt Haines finished three-under to make his first cut in 19 attempts this season.