A birdie at the last saw Ernie Els retain his place at the top of the leaderboard on day two of the BMW International Open in Munich.

The South African began the day with a one-stroke lead on nine under, only to see it overtaken by morning starters Danny Willett, the defending champion, and Austrian Bernd Wiesberger.

After five successive pars a birdie took him to 10 under, but he immediately dropped back with a double-bogey six at the 441-yard next.

The 43-year-old, who will defend his Open title at Muirfield next month, regained that stroke at the ninth and added four more birdies coming home - with his four at the 568-yard last enough to take him ahead of the pack after a bogey at the 16th had appeared to impair his progress.

He finished the day 12 under and one ahead of England's Matthew Baldwin and Frenchman Alexander Levy, who had rounds of 69 and 68 respectively.

Willett's 65 lifted him to 10 under and well placed to retain his crown while home favourite Martin Kaymer, struggling with illness, is a shot further back after a 71.

Ireland's Peter Lawie in very much in contention after his round of 69 left him on eight under and four shots off the lead. Shane Lowry and David Higgins are both two shots further back, while Gareth Maybe missed the cut on two under.

"I'm in a nice position obviously," Els told europeantour.com.

"I think it's going to play a little tougher over the weekend.

"It's getting a little bit firmer but I would like to swing a little better tomorrow, but I'm in a really nice position.

"I'm quite fortunate to be where I am. I didn't play as good today as I did yesterday obviously. I fought hard for a score and satisfied with that.

"There is so much golf to be played. If you fall out of the lead, if you're not leading after three rounds, it doesn't really mean much at all late Sunday.

"So you just want to stay in the race and keep trying to go forward."

Yorkshireman Willett's opening 69 had left him six strokes off the pace set by Els but he set out to change that as one of the morning starters.

Birdies at the 11th and 12th, having begun on the back nine, got the 25-year-old going but he had to wait until the first before he picked up another shot.

That was one of five birdies coming home which saw him leap 46 places to the top of the leaderboard.

"Yesterday was a little bit hit and miss. I haven't played a lot of tournaments in the last 14 weeks," said Willett, who has been affected by a back problem.

"It was a bit rusty but I hit a lot of good shots. It is good to put yourself in a good position playing sensible golf.

"It is a birdie-fest out here. People make a lot of putts and the greens are obviously better in the mornings than the afternoons, but if you can keep hitting it inside 15-20 feet you have a chance."

Kaymer failed to take advantage of an earlier start, managing to improve his score by just one after a one-under 71.

However, the German was satisfied with his position going into the weekend.

"The course has played longer, there was more wind and the pins are the biggest difference - today you have to play more conservatively," he said.

"My game was similar to yesterday, I just didn't make as many putts. It was definitely tougher to play but it is fine.

"Overall I am playing okay but I'm not feeling very well."