Marcel Siem of Germany shot a 3-under 69 Saturday to extend his lead to four shots after the third round of the Hassan II Trophy.
The French Open champion made five birdies but was pegged back by a bogey on the first hole and again on No. 17 to move to a 15-under total of 201 in the European Tour event.
''I got over a tough start with tough conditions and all the guys just behind me seemed to start really well and almost caught me up,'' Siem said. ''I had to hole a few big putts just to stay ahead and then I managed to pull away a little bit. But then 15 and 17 were disappointing because you are really looking to pick up a couple of shots there, but I managed to give one away.''
Mikko Ilonen of Finland, Englishman David Horsey, and Pablo Larrazabal of Spain were all tied for second on 205.
Ilonen is confident he can close the gap in Sunday's final round and challenge for victory.
''I am four back and would rather be a little bit closer, but we have three guys four behind that can catch him,'' Ilonen said. ''One of us will have to go really low tomorrow and I think the golf course will allow that. I have made enough birdies and eagles to know I can do it, but I just have to avoid the mistakes.''
Larrazabal matched Siem's score of 69, while Horsey and Ilonen — who were tied for second overnight — shot 70s.
