THIRD ROUND LEADERBOARD: GB & Ire unless stated
-12 R Karlsson (Swe) -9 J-F Lucquin (Fra), F Moliari (Ita) -7 P Ilonen (Fin), R Fisher, JM Lara (Spn), M Campbell (NZ) -5 P Hanson (Swe) -3 S Hansen (Den)
Karlsson's last tournament win was two years ago
Robert Karlsson is on course to end a two-year winless run despite incurring a one-shot penalty after round three of the Mercedes Benz Championship.
His round of 67 became a four-under 68 for a 12-under total when a shot was added to his score at the second hole, based on television footage.
When putting, he grounded his putter as his ball moved, adding an extra shot.
European Masters winner Jean-Francois Lucquin and Francesco Molinari are tied in second on nine under par.
Engand's Ross Fisher is in a group of players, including New Zealand's Michael Campbell, on seven under.
Karlsson collected seven birdies in his round before bogeying the final hole and having his second-hole bogey upgraded to a double, but he said he was happy with his day's efforts.
"It could actually have been worse, a two-shot penalty or disqualification, so I'm relieved in a way," said the Swede.
"I knew the ball had moved but didn't think I was in the wrong. As I always do, I placed the toe of my putter to the side of the ball not behind it."
Despite his lack of wins, Karlsson's consistent finishing this season has earned him a Ryder Cup spot, and several of his European team-mates have also shown encouraging form in Germany.
Soren Hansen, who won this tournament last year, is nine shots adrift of the lead on three under but carded 10 birdies in his second round.
Spain's Miguel Angel Jimenez is on the same score after his best round of the week, a 68.
And Ryder Cup debutant Graeme McDowell is one under after a round of 70.