Castleford (22) 56
Tries: Chase 4, Dixon, Mathers, Thompson, Owen, Clark, Milner
Goals: Dixon 8
Harlequins (18) 24
Tries: O'Callaghan, Riley 2, Wilkes 2 Goals: Gale 2
Castleford ran in 10 tries as they ended their four-match losing Super League run against hapless Harlequins.
Rangi Chase led the way with four of them, while Kirk Dixon, Richie Mathers, Jordan Thompson, Richard Owen, Daryl Clark and Adam Milner all crossed too.
On his Quins debut, on-loan Warrington winger Chris Riley scored twice, as did Oliver Wilkes, after a lung-bursting early beauty from Jamie O'Callaghan.
But Quins' sorry run without a league won now stretches to 10 games.
Their season was badly derailed by their record 82-6 defeat at Warrington on 20 March. And not even the inclusion of Riley, alongside fellow loan men Lee Mitchell and Karl Pryce, ineligible for the 40-20 Challenge Cup defeat at Leeds last weekend, could stop the rot.
Quins took a second-minute lead when full-back O'Callaghan collected Adam Milner's kick behind his own try line and eluded two tacklers in the in-goal area before going the length of the field to score a spectacular try.
After leading 14-6 midway through the first half, Quins were still only 22-18 behind at half-time.
But Kiwi stand-off Chase took control after the break to maintain Quins' miserable run.
Like Cas, Quins were early season table toppers before Warrington took control, winning four of their first five games.
But, since winning 27-16 at St Helens on 11 March, Quins' only Super League point in two and a half months was against Cas in a 26-26 draw at The Stoop in mid-April.
Cas coach Terry Matterson was not entirely happy, despite his side's first victory in six league games, insting that the Tigers can still play better.
The Tigers welcomed back prop Jonathan Walker from a 12-match injury lay-off but they suffered a blow when Samoan centre Willie Isa was stretchered off with an ankle injury in the second half.
Castleford coach Terry Matterson:
"It's great to score 56 points and, when we have the ball, we are really hard to defend against. But, over the last three or four weeks, we've hardly held any ball and it was the same in the first half today.
"Rangi Chase was a lot more controlled today but there some things we've got to do a lot better. We won by 32 points but to concede 24 points was very disappointing.
"We are keeping our fingers crossed that Willie Isa's injury is not too serious. He gives us solidarity and gives other people confidence around him.
"I was pleased to see Jonathan Walker back as we've lacked fire power and size up front. It's an important factor when you're playing the big teams. And I thought Jordan Thompson's impact from the bench was really good."
Harlequins coach Rob Powell:
"We were pretty good in the first half and I felt we were unlucky to be behind at half-time. But I was disappointed with the second period.
"Rangi Chase started doing his bits and dominated the game. When he does that and Castleford get a roll on they are a difficult team to play against.
"And we didn't cope well with it because we used up much our energy defending the kicks. It showed the massive effect of quality kicking. The difference in the two kicking games was a massive part. It just drained too much juice out of us defending repeat sets."
Castleford: Mathers; Dixon, Isa, Arundel, Owen; Chase, Orr; Fozzard, Milner, Emmitt, Jones, Ferres, Snitch.
Replacements: Walker, Thompson, Widders, Clark.
Harlequins: O'Callaghan; Melling, Pryce, Clubb, Riley; Bailey, Gale; Temata, Randall, Ward, Burnett, Mitchell, Wilkes.
Replacements: Ambler, Krasniqi, Ellis, Koupartisas.
Referee: Robert Hicks (Oldham).