AGADIR, Morocco --
Siem shot a 2-under 70 in the final round to hold off the challenge of Finland's
The French Open champion was four shots clear overnight but had a slow start with a bogey on the first, and was soon caught by Ilonen. However, three birdies from Siem and a mid-round slump from Ilonen saw the German carve out a decisive lead.
Siem finished with a 17-under total of 271 for his first wire-to-wire victory.
"I'm super happy, really proud that I stayed that calm," Siem said. "There was a lot of pressure, Mikko had a great start again, so I'm really happy that I scrambled well and came back nicely.
"I've never been in that situation so I spoke to Bernhard (Langer) last night to see if he could give me some advice on how to cope with being four shots in the lead, so thanks Bernhard."
The 72nd-ranked Siem now has to wait for the end of the Houston Open to see if the win enough to get him into the top 50, which would earn him a first spot at the Masters.
"That will be unbelievable," Siem said. "It's been my dream since I was a kid so if that comes true it will be unbelievable. It would be wonderful to play the Masters. I just want to be on that ground. I'm not going to cry but it would be very emotional."