Dutch Chess Master

Hi I work with a guy who said his grandfather was a Dutch Grandmaster and beat Bobby Fischer twice,  he isn't someone who would make this up, he didn't even know I played chess. This guy doesn't know his name and I was inquiring if maybe someone would. Do you know any Dutch GMs?  His first name was Johannas. 

Johannes van den Bosch?

Max Euwe was Dutch, and had a lifetime tournament/match score of one win, one draw and one loss against Fischer. If he also won an off-hand game, that might be it.

Jan-Hein Donner: https://en.m.wikipedia.org/wiki/Jan_Hein_Donner

Had at least one win against Fischer. His writing is great - collected into a volume called 'The King', which Silman called the best book ever written on chess. 

"His first name was Johannas."

And the answers are:

Anish Giri

Max Euwe

Jan Donner

Jan Hein being short for Johannes Hendrikus. 

Since you posted, i figured you would know that :-) I was curious how others would answer.

Ill run Johaness Henrikus by him and see if it rings the bell.

Let us know, im curious.

We think it's Jan Hein considering he was named after his grandfather