The first Challenge Cup semi-final will take place on Friday night when Leicester Tigers and Ulster go head-to-head at Welford Road.

The first European Challenge Cup semi-final will take place on Friday night with Leicester Tigers hosting Ulster at Welford Road.
Leicester club captain Tom Youngs starts alongside Ellis Genge and Dan Cole in the front-row, with Harry Wells and Calum Green making up an unchanged Tigers tight-five from last weekends Premiership game against Northampton Saints.
George Martin returns at blindside flanker, which sees Hanro Liebenberg move to openside and Jasper Wiese retain his place at number eight in the Leicester back-row.
Richard Wigglesworth, who missed last weekends derby, comes into the Tigers side at scrum-half to partner fly-half George Ford. Matt Scott is joined by Matías Moroni in the midfield.
Nemani Nadolo, who came off the bench to score two tries against Northampton, and Guy Porter are the wings and Freddie Steward is at full-back.
Charlie Clare, Luan de Bruin, Joe Heyes, Tomás Lavanini and Cyle Brink are the forwards replacements, with Ben Youngs, Zack Henry and Kini Murimurivalu the backs on the Tigers bench.
Meanwhile, Ulsters starting team sees five changes to the side that featured in their PRO14 Rainbow Cup opener against Connacht last Friday.
Eric OSullivan and Marty Moore return to the starting front-row, while Rob Herring is retained at hooker. Iain Henderson will captain the side and is joined by Alan OConnor in the engine room.
Matty Rea retains his starting berth at blindside flanker, with Jordi Murphy returning to the openside position, and Nick Timoney completing the base of the pack at number eight.
The starting back three remains unchanged; Jacob Stockdale is named at full-back, with Ethan McIlroy and Robert Baloucoune on the wings. Stuart McCloskey comes back into midfield to pair up with James Hume. John Cooney starts at scrum-half with Billy Burns at fly-half.
Providing the forward reinforcements from the bench are John Andrew, Andrew Warwick, Tom OToole, Kieran Treadwell and Sean Reidy. Alby Mathewson, Michael Lowry and Will Addison will offer backline cover.
The teams:
Leicester Tigers: 15 Freddie Steward, 14 Guy Porter, 13 Matias Moroni, 12 Matt Scott, 11 Nemani Nadolo, 10 George Ford, 9 Richard Wigglesworth, 8 Jasper Wiese, 7 Hanro Liebenberg, 6 George Martin, 5 Calum Green, 4 Harry Wells, 3 Dan Cole, 2 Tom Youngs (c), 1 Ellis GengeReplacements: 16 Charlie Clare, 17 Luan de Bruin, 18 Joe Heyes, 19 Tomas Lavanini, 20 Cyle Brink, 21 Ben Youngs, 22 Zack Henry, 23 Kini Murimurivalu
Ulster: 15 Jacob Stockdale, 14 Rob Baloucoune, 13 James Hume, 12 Stuart McCloskey, 11 Ethan McIlroy, 10 Billy Burns, 9 John Cooney, 8 Nick Timoney, 7 Jordi Murphy, 6 Matt Rea, 5 Iain Henderson (c), 4 Alan OConnor, 3 Marty Moore, 2 Rob Herring, 1 Eric OSullivanReplacements: 16 John Andrew, 17 Andy Warwick, 18 Tom OToole, 19 Kieran Treadwell, 20 Sean Reidy, 21 Alby Mathewson, 22 Michael Lowry, 23 Will Addison
Venue: Welford RoadKick-off: 20:00 BST (19:00 GMT)Referee: Pascal Gauzère (France)Assistant referees: Romain Poite (France), Alexandre Ruiz (France)TMO: Eric Gauzins (France)