Trinity have been in freefall since losing at London Broncos in May and the 26-16 home loss to Hull was their 10th reverse in 11 league games and fifth in succession.
They remain just two points above bottom club London.
Wakefield face a huge game at second-bottom Hull KR next week and then take on Wigan Warriors and Warrington Wolves before playing host to London in their final fixture.
They have a much better for and against than London and safety is still in their hands, but it is getting too close for comfort.
They weren’t much worse than third-placed Hull, but a poor spell either side of the break cost them any chance of victory in a dire game.
Hull’s purple patch of four tries in 11 minutes wiped out an early Trinity lead and left them 14 points adrift at the break.
They went 20 behind in the third quarter before finally showing signs of life with a couple of late tries which will give them something to build on.
The game was littered with errors – from both teams – throughout, but Trinity, including debutants Morgan Escare and Adam Tangata, got off to a positive start when Ryan Hampshire scored from a scrum around halfway.
Danny Brough added the extras, but Hull took a grip on the game after scrambling an equaliser on 19 minutes. Bureta Faraimo got them on the board, touching down from Jake Connor’s pass after Marc Sneyd’s kick had rebounded off a post.
On 24 minutes Josh Griffin’s fumble led to a scrum 30 metres from Hull’s line, but directly from that Hampshire’s pass was intercepted by Carlos Tuimavave and he went all the way to score.
Sneyd landed two 40-20s in the opening 27 minutes. The first was wasted when Masi Matongo knocked-on on play one; the second came in the set from Tuimavave’s touchdown and was more fruitful.
Jacob Miller and Joe Arundel held Connor up over the line, but on the next play Sneyd’s footwork too him through a static defence.
Hull scored again on the half-hour when Connor and Tuimavave combined to send Ratu Naulago over. Sneyd improved the first and third tries and, at 20-6 down, Trinity were in trouble.
Trinity were pressing on 11 minutes when Escare’s pass was intercepted by Tuimavave. He gave it to Naulago who should have gone nowhere, but spun out of some feeble attempted defence and cruised 80 metres for a converted try which made the gap 20 points. That completed Hull’s scoring and Trinity pressed after that, to grab two consolation tries.
Arundel went over from Bill Tupou’s pass and Miller touched down Hampshire’s kick seven minutes from time, Brough converting, but it was too little, too late.
Hull were allowed only seven interchanges – one fewer than Trinity.
They were deducted one for a change to the line-up on their teamsheet, Matongo starting and Josh Bowden dropping to the bench.
Wakefield Trinity: Hampshire, Jones-Bishop, Lyne, Tupou, Escare, Miller, Brough, Tanginoa, Wood, Kopczak, Kirmond, Arundel, Batchelor. Subs Randell, Fifita, Tangata, Annakin.
Hull: Shaul, Faraimo, Griffin, Tuimavave, Naulago, Connor, Sneyd, Taylor, Houghton, Matongo, Lane, Minichiello, Ellis. Subs Bowden, Fash, Washbrook, Brown.
Referee: Liam Moore (Wigan).