Wakefield (10) 10
Tries: Blanch, George Goal: Cooke
Crusaders (10) 20
Tries: Thomas, Witt, Youngquest, Mellars Goals: Witt 2
Gareth Thomas was making only his fourth rugby league appearance
Union convert Gareth Thomas celebrated his first try in league as Crusaders secured their second Super League away victory of the season at Belle Vue.
Damian Blanche hit back after Thomas's opener, Paul Cooke putting the home side in front with his conversion.
Michael Witt restored Crusaders' lead before Luke George's converted try levelled it 10-10 at the break.
But tries from Nick Youngquest and top scorer Vince Mellars after the interval took Brian Noble's men clear.
Mellars' seventh try of the campaign put the seal on a fourth win of the campaign for 10th-placed Crusaders.
The visitors broke the deadlock on six minutes after a penalty secured them good field position and slick handling saw Thomas crash over in the right corner.
Scrum-half Witt missed the touchline kick.
Wakefield went in front on 15 minutes when another penalty gave them a rare foray into their opponent's half.
Blanch's try was converted by Cooke but just three minutes later his grubber deflected into Witt's hands and he raced away to score.
Cooke's boot was instrumental again when his kick from a penalty set up a good position and George took a short try-scoring pass 25 metres out.
A loose kick from the Wildcats again proved their downfall 14 minutes after the turnaround as Youngquest picked up and sprinted the length of the field.
Witt added the conversion to put Crusaders 16-10 ahead.
An error-strewn second-half from Wakefield was capped off when a dropped ball led to a turn-over in midfield and Mellars ended the Welsh side's set by crashing over for an unconverted try.
Wakefield head coach John Kear:
"We are in a hole and we are not showing signs of getting out of it at the minute.
"We are obviously missing personnel we started the season with but we are not showing signs that we are improving, we are just showing signs that we are deteriorating.
"I hope it is hurting the players because it certainly wasn't acceptable for the fans who pay their hard-earned money to come here and watch that."
Crusaders coach Brian Noble:
"I thought we were unlucky last week and the week before and we tried our best to lose this one.
"We worked really hard and I am thoroughly pleased but we could have made the game a whole lot easier for ourselves."
Wakefield Trinity Wildcats: Wakefield: Blaymire, Blanch, Murphy, Millard, George, Jeffries, Obst, Moore, Leo-Latu, Korkidas, Demetriou, Morrison, Cooke.
Replacements: King, Henderson, Tronc, Kirmond.
Crusaders RL: Schifcofske, Thomas, Chan, Mellars, Youngquest, Lupton, Witt, O'Hara, O'Hara, Withers, Bryant, Hauraki, Winternstein, Trimarchi.
Replacements: Peek, Flower, Thackray, Hanbury.
Ref: Gareth Hewer (Whitehaven).