It was the visitors who got off to a bright and physical start in the drizzly conditions, but after fly half Danny Gray opened the scoring with an easy chance the Wanderers were soon on top.
While Jamie Elliott was pulled back in full flight for a forward pass, the pressure stayed on and a pair of tries came in quick succession. First time round it was Waller against the base of the post scoring for the second consecutive Monday evening, and when Cesar Sempere sliced through Pisi was on hand to barge over for a second.
Myler converted both but with no further score in the first half, it wasn't until the 44th minute that the Wanderers fly half extended the lead with a straightforward three-pointer.
Worcester showed good resilience and forged some chances of their own, but with Scott Armstrong and Pisi tackling well in defence, Sempere led a rapid counter that almost saw Greig Tonks play in Elliott.
The third score looked to be coming, but the Wanderers were frustrated for a good 15 minutes before they finally got it - Haywood splitting off the back of an unstoppable maul for the try.
That left the home side in sight of a bonus-point - one that narrowly escaped Pisi on the left as he reached out for the line - and after a knock in the final play, the Wanderers had to content themselves with a second straight Monday night win.
3mins WORCS Pen Gray 0-3
25mins WAND Try Waller Con Myler 7-3
29mins WAND Try Pisi Con Myler 14-3
HALF-TIME WANDERERS 14 WORCESTER 3
45mins WAND Pen Myler 17-3
67mins WAND Try Haywood 22-3
FULL-TIME WANDERERS 22 WORCESTER 3