Hull FC finished the regular Super League season on top of the table after beating Salford Red Devils 28-20, while St Helens claimed a 23-4 derby win at Wigan Warriors on Friday.
Lee Radford's side headed into the clash at Salford ahead of Wigan on points difference and sealed top spot after outscoring the hosts by five tries to four.
Steve Michaels and Frank Pritchard touched down either side of a Michael Dobson score to give the leaders a 12-6 advantage at the break.
Salford, who announced the signings of Manly Sea Eagles duo Luke Burgess and Feleti Mateo ahead of the match, were just two points behind when Mason Caton-Brown touched down 13 minutes into the second half.
The Red Devils were in front following scores from Niall Evalds and Rob Lui after Chris Green had gone over for Hull, but Marc Sneyd, who also booted eight points, and Mahe Fonua added further tries to give Hull another victory.
Saints stretched their winning run to five matches by coming out on top in a feisty derby against last year's runners-up at the DW Stadium.
Mark Percival scored a try and 10 points with the boot, while Morgan Knowles and James Roby also dotted down for Keiron Cunningham's side to move them up to fourth heading into the Super 8s.
Wigan, who could only muster a Lewis Tierney try, remain second but Warrington Wolves will go above them if they beat Huddersfield Giants on Saturday.
It was a home debut to forget for Frank-Paul Nuuausala after he was sent to the sin-bin for striking Louie McCarthy-Scarsbrook, who was also yellow-carded as tempers flared.