Van Gerwen averaged 100 so not towards his full capability but with Chisnall averaging only 84 with his scoring power not there in the slightest.
This was shown with zero 180's and he only got three darts at double throughout the contest hitting one of them which was a 100 finish.
'Mighty Mike' on the other hand hit four 180's and 36 percent on the double which in reality was the difference against an out of sorts St Helens thrower.
He will now take on James Wade, who has beaten him on recent occasions this year or Joe Cullen, who has returned to form this weekend.
Click here for more information about the PDC European Tour, including the format, calendar and the prize fund breakdown.
Michael van Gerwen (100.13) 6-5 (93.09) Krzysztof Ratajski
Rob Cross (87.09) 5-6 (90.14) Dave Chisnall
Jonny Clayton (84.79) 4-6 (93.27) James Wade
Joe Cullen (99.29) 6-2 (98.72) Glen Durrant
Semi-Finals
Michael van Gerwen (100.25) 7-1 (84) Dave Chisnall
James Wade v Joe Cullen
Final
Michael van Gerwen v Wade/Cullen