Full-back Thewlis, who was filling in for the injured Stefan Ratchford, scored three tries as the Wolves bounced back from a narrow defeat at Hull FC on Easter Monday.
There were two notable milestones for Warrington’s Daryl Clark and Josh Charnley. Hooker Clark was making his 200th appearance for the club, while Charnley made his 300th career appearance, with 107 of those for the Wolves.
Huddersfield, who started with former Warrington skipper Chris Hill, really struggled to settle in a game where they were reduced to 12-men on two separate occasions – Australian Jack Cogger sin-binned twice in the first half.
Cogger walked for the first time in the seventh minute for a professional foul and Wolves took advantage of the extra man with a try moments later.
Thewlis crossed over from dummy half after Matty Ashton had been stopped inches short just seconds earlier. With Warrington’s three regular kickers all out injured – Ratchford, Williams and Widdop – Dean stepped up to attempt the conversion but he was off target.
Warrington extended their lead thanks to an eight-point try in the 19th minute and once again Dean was involved, linking the play nicely and sending Thewlis over in the corner. Dean missed the conversion but kicked a penalty which was awarded after Cogger committed a foul after the try was scored meaning a second trip to the sin-bin for the Huddersfield half-back.
On the half hour, Warrington added their third try. A teasing grubber kick to the corner by Dean sat up perfectly for Toby King and he was able to collect the ball and touch down. Dean added the conversion and a penalty moments later after the Giants were pulled up for ball stealing.
At 18-0 down, Huddersfield were desperate for a response and they produced it three minutes before half-time. Some quick passing along the left edge ended with Innes Senior scoring out wide though Olly Russell was off target with the conversion.
Warrington took a while to find their first-half groove after the restart but they improved as they half went on, adding three more tries in the final 22 minutes.
Connor Wrench finished off a slick attack before Thewlis wrapped up his hat-trick, grounding another well-placed kick from the lively Dean. A fourth goal from Dean meant Warrington led 28-6.
With 10 minutes remaining, Ben Currie ran a great line to race in from 15 metres, though Dean’s conversion fell just short.
Huddersfield, who have not won in Super League since April 1, claimed their second try four minutes from the end when Luke Yates charged over from close range and Russell added the conversion.