Hull (6) 6
Tries: Tickle Goals: Tickle
St Helens (14) 30
Tries: Lomax, Wellens 3, Gilmour, Fa'asavalu Goals: Long 3
Wellens has now scored 10 tries in six games for Saints
St Helens moved three points clear at the top of the Super League table after a comfortable win over Hull.
Paul Wellens scored a hat-trick to help give his side their 15th consecutive away win and equal Bradford's Super League record, set in 1997.
Teenager Jonny Lomax also went over for his debut try after a flowing move that involved Sean Long, who will play for Hull next season.
Lee Gilmour and Maurie Fa'asavalu crossed late on for the visitors.
Saints made a sluggish start and were forced to absorb some early Hull pressure before a flowing move allowed Lomax to cross, but Long was unable to convert from the touchline.
The former Great Britain international, who earlier this week signed a two-year deal at the KC Stadium, then created a try for Wellens with a slick inside ball after a break by Jon Wilkin and added the extras.
Hull went close through Chris Thorman but Danny Tickle cut the gap with a try after a pass from Richard Horne that looked forward and he kicked the goal himself.
But Saints scored a crucial try just before the break with Wellens darting over moments after Long's weaving run and although they continued to dominate after the break, it took until the 53rd minute for them to score again.
Long's high bomb bounced into the arms of Wellens who gratefully completed a first hat-trick of the season.
Kieron Cunningham, one of only two players to have played in all 15 away wins, went close, before Long laid on simple try for Gilmour which leaves him on 49 for the club.
Long failed with the goal, but was able to slot his third of the game with five minutes remaining after he and Matty Ashurst had combined to send Fa'asavalu cantering over for a score that completed Hull's misery.
Hull coach Richard Agar:
"I wasn't paying too much attention to Sean. I got more satisfaction from our own number seven's performance (Chris Thorman).
"He was massively under the pump and I thought it was a real test of his character. We've signed Sean, Chris is out of contract and under scrutiny and not been in great form and I thought he showed some balls with his performance.
"We've announced a couple of signings and I'd like to think next year's squad is taking shape but I'm more concerned about making the (top) eight this season."
St Helens coach Mick Potter (on full-back Paul Wellens):
"I thought he showed he is a quality player and fits in well with us.
"He's a player who's played a lot of games and knows what to do. His anticipation is second to none. There are not too many better than him.
"I thought it was a very tough match, the score probably didn't reflect how tough it was. I thought defensively we were very good and in attack we've got a little bit more work to do.
Hull: Tony, Calderwood, Whiting, Yeaman, Raynor, R. Horne, Thorman, Dowes, Berrigan, Thackray, Burnett, Tickle, Radford. Replacements: Houghton, King, Lee, Maloney.
St Helens: Wellens, Lomax, Gidley, Gilmour, Meli, Pryce, Long, Graham, Cunningham, Hargreaves, Wilkin, Flannery, Puletua. Replacements: Fa'asavalu, Roby, Clough, Ashurst.
Referee: P Bentham (Warrington)