It was their fourth consecutive victory, whilst they also broke their Super League away win record as they picked up their ninth win away from home.
The game was a vastly damp affair, the miserly weather preventing any expansive play from either side, but Castleford made better use of the conditions.
Both sides struggled to keep hold of the ball in the slippery conditions, but Wakefield squared matters after a couple of penalties helped them further up the field, and Danny Brough skipped through a gap.
A penalty from Westerman was the only addition to the scoreline during the rest of the first-half although Michael Wainwright stopped Wakefield from scoring, making a superb tackle to drag Scott Grix into touch.
With a two point deficit, the game was finely poised but it was the Tigers who gained the advantage again, Widders again the scorer after he powered his way over. Westerman once more added the conversion, and then tagged on another penalty five minutes later.
But Wakefield never gave in and got rewards for their efforts when Brough managed to cross again as the momentum started to swing their way.
Castleford did find brief respite again, tagging on another Westerman penalty to give them a six point advantage, but that could have easily been wiped out if James Evans had not made another sublime tackle as Wakefield looked set to score in corner.
But that proved to be as close as Wakefield were going to get despite a couple of testing kicks from Brough and Brad Drew.
And Terry Matterson’s men sealed victory with another Westerman penalty, Wakefield guilty of holding down.