The Vikings, who put some indifferent recent form behind them with a 26-12 win over Barrow on Thursday night, face a trip to Keighley, who earned their place in the final four with a 32-6 win over York.
Leigh recorded a comfortable 42-6 win away at Hunslet to keep their cup bid alive, knowing that winning the competition will satisfy the on-field criteria of the Super League application process.
They will host Batley who defeated Sheffield 26-16 at Mount Pleasant.
The semi-finals take place on the weekend of June 20th, with the final at Blackpool’s Bloomfield Road on July 18th.
Widnes 26-12 Barrow
Batley 26-16 Sheffield
Hunslet 6-42 Leigh
Keighley 32-6 York
Keighley v Widnes
Leigh v Batley