Rhinos v Saints: Teams
The tie of the round comes from Headingley Carnegie as new league leaders Leeds Rhinos host former table-toppers St Helens on Saturday.
While the Rhinos won both of their Easter programme fixtures, two defeats for Saints meant they surrendered top spot to their fierce rivals.
Last season's meetings at Headingley were split with Leeds knocking St Helens out of the play-offs, although Nathan Brown's men secured a 14-10 triumph over the Rhinos last month courtesy of Tommy Makinson's late try.
St Helens (12) have one more Challenge Cup success than Leeds (11) and have won the trophy five times since Leeds last lifted the trophy in 1999. The Rhinos have remarkably lost all six finals contested since beating London Broncos at the old Wembley.
Leeds head coach Brian McDermott has brought back centre Kallum Watkins, who was rested for Monday's win over Salford, while forward Ian Kirke is hoping for a recall after being 18th man against the Red Devils.
The Rhinos remain without hooker Paul Aiton, Jamie Jones-Buchanan (bicep) and Stevie Ward (ankle).
"This has been building since Saints and us were drawn out of the hat together," McDermott said. "Both teams have got through the league as best they could and have been looking forward to this one ever since."
"They won their first eight so they're a very good team. We'll prepare for a very good Saints and maybe the game will go down to the wire."
Saints are boosted by the return of Luke Walsh, Alex Walmsley, James Roby and Jonny Lomax, who were all rested for the Easter Monday game at Widnes, while Jordan Turner, Kyle Amor and Adam Swift are expected back after missing the Easter programme through injury.
Only forwards Willie Manu and Anthony Laffranchi are definitely missing for Brown's men.
"Every time we play Leeds it is a close game," Brown told the club's official website. "Since I have been at Saints we have won a couple and they've done the same. Every game has been a good game of footy and this one will be no different.
"The respect from club to club is high. Our away support has been brilliant and they will travel in numbers again. It is a big tie at a great place, on a great field and I have no doubt the winner would fancy themselves to push through and have a genuine chance of going to Wembley."
Leeds Rhinos: Hardaker, Jones-Bishop, Watkins, Moon, Hall, McGuire, Burrow, Leuluai, Peacock, Ablett, Sinfield, Delaney, Bailey, Kirke, Clarkson, Achurch, Briscoe, Sutcliffe, Singleton.
St Helens: Lomax, Makinson, Turner, Jones, Swift, Hohaia, Walsh, Masoe, Roby, McCarthy-Scarsbrook, Soliola, Wilkin, Amor, Wellens, Walmsley, Percival, Greenwood, Richards, Thompson.