St Helens secured their place in the play-offs for the 20th consecutive year after defeating 12-man Salford 30-4.
Alex Walmsley scored two tries as they defeated Ian Watson’s side, who spent the duration of the second-half a man down after Ryan Lannon was sent-off for a late challenge on Theo Fages.
That incident came a minute after Salford called for Walmsley to be punished for an incident involving Tyrone McCarthy, although referee James Child placed the incident on report.
It leaves just one place in the play-offs up for grabs, with Hull FC able to secure that spot should they defeat Castleford on Friday.
Niall Evalds put Salford ahead, but Saints hit back through Percival and Walmsley before Lannon was given his marching orders.
Zeb Taia, Walmsley and Ben Barba all scored in the second-half to ensure Saints’ perfect play-off record remained intact.
Salford: Evalds, Bibby, Welham, Sa’u, Vatuvei, Lui, O’Brien, Murray, Tomkins, Hauraki, Murdoch-Masila, Jones, McCarthy. Subs: Kopczak, Brinning, Lannon, Walne.
St Helens: Barba, Makinson, Morgan, Percival, Grace, Fages, Richardson, Thompson, Roby, Douglas, Knowles, Taia, Wilkin. Subs: Smith, McCarthy-Scarsbrook, Walmsley, Peyroux.
Tries: Walmsley (2), Percival, Taia, Barba
Goals: Percival (5)