The two sides who swapped places ahead of the 2017 season go head-to-head in round five of the Ladbrokes Challenge Cup this year.
While Leigh, League Leaders in the Kingstone Press Championship last season, stormed to promotion through the Qualifiers, Hull KR went on to suffer heartbreak in a dramatic golden point loss to Salford Red Devils in the Million Pound Game.
The two sides faced off last year in the Qualifiers when Leigh produced a stirring performance to win 25-18 away from home, while they clashed at the Leigh Sports Village in 2015, with Rovers coming from a 24-6 half time deficit to win 36-26.
Both sides have a proud recent history in the Challenge Cup; Leigh giving Leeds Rhinos a scare in losing 25-12 at Headingley in the quarter finals three years ago, while they captured the imagination by beating both Salford and Wakefield on their way to a memorable 34-24 loss at Warrington in the quarter finals.
Rovers, meanwhile, were on the end of a shock 36-22 home defeat by Oldham last year, but did make it all the way to Wembley in 2015.
KR have lost just once in the Championship this season, while Leigh have lost their last five games in Super League, but the visitors will come into the game as underdogs.
Hull KR stunned Super League giants Warrington 40-36 as a Championship side back in 2006 - can they pull off another shock on Saturday?
Toronto Wolfpack's biggest test to date comes this weekend as they travel to face in-form Salford.
After squeezing past Siddal from the National Conference League 14-6 in round three, the Canadians pulled off a shock 30-26 win at London Broncos in round four to set up this round five clash.
Toronto come into the game having never lost a competitive match, running in 60 points in the first half of their 80-0 win at North Wales Crusaders last weekend.
They could also field newest signing Ryan Brierley after he completed a move from Huddersfield Giants this afternoon. He brings more Super League experience, alongside the likes of fellow recent addition Ryan Bailey.
But Salford are set to provide Paul Rowley's men with their stiffest test yet.
The Red Devils have bounced back in style after dramatically saving their Super League status last year and sit third in the Betfred Super League table, with a 54-18 win at Hull FC being their headline result so far this season.
The Heavy Woollen Derby takes place for the second time in as many weeks as Batley travel to Dewsbury's Tetley's Stadium.
The Rams won the Good Friday clash 20-4 on home turf, the first time they have picked up a league win this season, and will be keen for a repeat under the stewardship of new coach Neil Kelly.
FT: Dewsbury Rams 20 Batley Bulldogs 4— Dewsbury Rams (@DewsburyRams) 14 April 2017
But Matt Diskin's side, who made it to the Qualifiers last year under John Kear are the only side to beat Toulouse on home turf in 2017 after they came up with a 34-16 win in France in the third round, and will come into the game as favourites.
Tickets for the 2017 Ladbrokes Challenge Cup final at Wembley Stadium on Saturday, August 26, can be purchased by calling the Rugby League Ticket Office on 0844 856 1113 or by visiting rugby-league.com/tickets.
The full schedule of Ladbrokes Challenge Cup fifth round fixtures is as follows:
Friday, April 21
Leeds Rhinos v Doncaster RLFC (8.00pm)
Saturday, April 22
Leigh Centurions v Hull Kingston Rovers (3.00pm)
Sunday, April 23 (all kick off at 3.00pm unless stated)
Salford Red Devils v Toronto Wolfpack (12.15pm)
Huddersfield Giants v Swinton Lions (12.30pm)
Featherstone Rovers v Oldham
Dewsbury Rams v Batley Bulldogs
York City Knights v Barrow Raiders
Whitehaven RLFC v Halifax RLFC (Live on BBC Sport website)