Stuttering Saints got their season started, but only after last year's bottom club were controversially reduced to 11 men.
A dour but intriguing battle was locked at 4-4 on the hour mark, with Widnes arguably the better of the two sides. But then Ben Cross went in high on Paul Wellens and virtually all the players on the pitch were involved in a brief but furious fracas.
After consulting with both his assistants, the referee, James Child, sent off Cross and dispatched his team-mate Jon Clarke to the sin-bin.
The Widnes coach, Denis Betts, did not believe it had been that one-sided a fight. "If he wanted to get his cards out, he could have made it 11 versus 11 – 11 versus 13 made it pretty tough," Betts said. "I thought we could have won it. The players feel it was one they let slip."
Predictably, the two-man advantage told and, after Jordan Turner had a try disallowed for a knock-on, Saints finally got their noses in front in the 68th minute when Lee Gaskell sold a dummy and straightened up to find a gap in an out-numbered defence.
Widnes, with Gareth Hock making his debut, kept plugging away and creating half-chances, but with time running out Jonny Lomax pounced on a loose pass from Dave Allen and fed Francis Meli for his second try of the match. Two goals from Gaskell completed a scoreline that flattered the visitors.
Saints, thrashed by Huddersfield last week, had also looked off-colour in the first half at the Stobart Stadium. Widnes had taken the lead after nine minutes, when Rhys Hanbury kicked high across field, Paddy Flynn beat the defence to the ball and served it up for Stefan Marsh.
The equaliser came eight minutes later when Wellens chimed in to the line and released Meli.
Defences were usually on top after that, but Saints' new coach, Nathan Brown, was just happy to get the win, especially without the injured James Roby.
"People will say it's only Widnes, but they really ripped into us today and played very well," Brown said.
That praise will be scant consolation for Widnes perhaps, but may be taken as a warning to the rest of Super League that they need to be taken seriously, particularly when they have 13 men on the field.
Widnes Try Marsh. St Helens Tries Meli 2, Gaskell; Goals Gaskell 2 Widnes: Briscoe; Flynn, Marsh, Phelps, Isa; Mellor, Hanbury; Cross, Clarke, O'Carroll, Allen, Leuluai, Cahill. Subs used White, Hock, Joseph, Gerrard.
St Helens: Wellens; Makinson, Turner, Jones, Meli; Gaskell, Lomax; Perry, Hohaia, Laffranchi, Soliola, Wilkin, Manu. Subs used Greenwood, Flanagan, McCarthy-Scarsbrook, Puletua. Referee: J Child (Dewsbury)