Hull (6) 27
Tries: Briscoe, Turner, Houghton, Manu, Tickle Drop Goals: Tickle Goals: Tickle 3
St Helens (22) 26
Tries: Meli 4, Cunningham Goals: Lomax 3
Danny Tickle scored 11 points to overturn St Helen's first-half lead
Danny Tickle helped Hull stage an astonishing second-half comeback to edge to victory over St Helens.
The home side opened the scoring through Tom Briscoe but Saints ran riot, Francis Meli adding a hat-trick to Keiron Cunningham's earlier try.
When the in-form winger went over for his fourth, a comeback looked unlikely.
But Hull went on to score 22 unanswered points to level the scores and Tickle struck a superb 78th-minute drop goal to snatch the win.
Mick Potter's side had what looked to be an unassailable 26-6 lead with little over 30 minutes remaining, only for the home side to respond with an unstoppable barrage that resulted in them registering three successive wins for the first time this season.
The result leaves Saints coach Potter with plenty of questions to answer as his side, missing England star Kyle Eastmond for the first time this season, badly lost their way in the second half.
Hull had no answer to the momentum Saints had built up in the first half, and once Meli had completed his four-try haul shortly after the re-start, the game seemed dead and buried.
But soon it was Saints turn to be rattled, Jordan Turner giving Hull hope when he went over with 32 minutes left.
Danny Houghton pounced on a loose ball after Sean Long's kick to slip in under the posts and bring his side back to within eight points.
Willie Manu brought Richard Agar's side even closer to them with a close-range bump over the line following Houghton's pass - although Tickle was unable to convert on this occasion.
Tickle quickly redeemed himself, as he pounced on another Meli handling error from a long kick to score in the corner, with another failed conversion tying the scores at 26-26.
Ex-Saints playmaker Long saw a drop goal attempt fall agonisingly short, before Tickle found the mark.
Hull coach Richard Agar:
"It was always going to be tough, but we said at half-time that it was a game of momentum.
"I thought that once we got a try we got some momentum and robbed it really well. We blasted them on possession.
"It was a great game and both teams came to play. We can take belief and confidence and our character and composure came through at the end."
St Helens coach Mick Potter:
"There was no real turning point. The weight of possession told. We got tired in the middle but the possession knocked us out in the end.
"I thought our effort was as good as we could have given. If we had our time again we would do a couple of things a little different.
"The effort and toughness was second to none and they can hold their heads up."
Hull: Tansey, Whiting, Turner, Yeaman, T. Briscoe, Washbrook, Long, Dowes, Houghton, O'Meley, Manu, Tickle, Fitzgibbon.
Replacements: Radford, Moa, Cusack, Hall.
St Helens: Wellens, Lomax, Gidley, Flannery, Meli, Pryce, Moore, Graham, Cunningham, Hargreaves, Dixon, Clough, Roby.
Replacements: Fozzard, Ashurst, Magennis, Wheeler.
Referee: Phil Bentham (Warrington)