Cory Patterson of Toronto Wolfpack celebrates a try with teammates.
Widnes' seven-year stay in Super League came to an end as they were beaten 20-12 by promotion-chasing Toronto at the Lamport Stadium.
The Vikings have flirted with relegation all year and ended the regular season eight points adrift at the foot of the table with just three wins.
They were handed the chance of a reprieve via the Super 8s Qualifiers but made the worst possible start with a home defeat by London Broncos and, although they grabbed a lifeline with victory over Halifax a week ago, defeat in Toronto sealed their fate.
With Toulouse and London Broncos also claiming victories over Super League opponents in round six, it means the make-up of the top tier in 2019 will now be decided in the last weekend of the season.
Salford host Toulouse on Thursday while Toronto, who finished eight points clear in the Championship, play Leeds at Headingley on Friday and London Broncos are at home to Halifax next Saturday.
The Vikings led 6-0 against the Wolfpack after second rower Chris Dean, back in the side after recovering from injury, offloaded from the tackle to get full-back Joe Mellor over for the game's opening try after 11 minutes.
Krisnan Inu added the conversion and also kicked a penalty after Toronto second rower Cory Paterson had brought the home side level with an 18th-minute try.
The home side were temporarily reduced to 12 men in the 24th minute when centre Chase Stanley was sin-binned for a crusher tackle on winger Owen Buckley, but they managed to regain the lead in his absence after a cut-out pass from Gareth O'Brien got winger Matty Russell over in the corner.
O'Brien failed with the conversion attempt and was also wide with a penalty as the Wolfpack reached the interval 10-8 in front.
Widnes regained the lead two minutes into the second half when Liam Finn's delayed pass got Dean through a hole in the Wolfpack defence for his side's second try and the game became frantic as both sides strove to gain the ascendancy.
Paterson thought he had scored his second try, but a last-ditch tackle from Sam Wilde forced the ball from his grasp over the line and at the other end Harrison Hansen forced his way over from close range, only to lose his grip on the ball.
The lead changed hands for a fourth and decisive time in the 56th minute when Toronto half-back Blake Wallace darted over from dummy half on the last tackle and O'Brien's conversion made it 16-12.
The Vikings were then denied when forward Chris Houston was held up over the try line and it proved to be their last chance as O'Brien's two late penalties secured the win for the hosts.
