Leeds scored two tries in the final five minutes to beat Castleford 14-8 and snatch a Betfred Super League play-off place from the Tigers' grasp.
In a winner-takes-all match for the final spot, Rhinos were first to blink in this low-scoring encounter when Jake Mamo put Castleford eight to the good in the 51st minute after Paul McShane earlier converted a penalty.
Time was beginning to run out for Leeds but they got their first points of the game in the 73rd minute through a Rhyse Martin penalty, and their first try followed just minutes later when Kruise Leeming drew level.
Rhinos plucked victory right at the death when Aidan Sezer flew underneath the sticks to win the game and secure the final play-off place.
St Helens scored four tries in the final 20 minutes as they came from 16-12 down to defeat an already relegated Toulouse 36-16 on the day they received the League Leaders' Shield.
Ilias Bergal, Nathan Peats and Eloi Pelissier gave the French side a lead but St Helens flexed their muscles with tries from Matty Lees, Konrad Hurrell, Jack Welsby and Tommy Makinson to add to Joe Batchelor and Curtis Sironen's earlier tries.
Hull KR claimed bragging rights over city rivals Hull with a convincing 36-4 victory at the MKM Stadium.
Both sides were level on points and unable to reach a play-off spot heading into the final game but Will Tate went over the whitewash twice alongside contributions from Ryan Hall, Ethan Ryan, Elliot Minchella and Albert Vete on his final appearance to cap off an emphatic victory.
Warrington claimed their first away victory since February with a 32-14 win over an understrength Salford side.
Josh Thewlis crossed over for a double and tries from Oliver Holmes, Luke Thomas, George Williams and Greg Minikin helped them round off the season with victory against the Red Devils, who included six debutants in their 17-man squad.
Wigan ended the regular season with a 100 per cent home record as they scored eight tries in a 48-4 victory over a young Catalans Dragons side, who had 10 players making their debuts.
The Warriors led 24 points to nil at the break thanks to tries from Harry Smith, Kaide Ellis and a Liam Marshall double.
Josh Drinkwater, Ethan Havard and Jake Bibby scored in the second half, alongside Bevan French who added a brace of his own as Wigan entered the play-offs in style.
Huddersfield claimed a dramatic 16-14 extra-time win over Wakefield and clinched a third-placed finish thanks to a late Will Pryce penalty.
Trinity were on course for their fifth straight win when they led 14-12 with a quarter of an hour to play but Pryce's penalty sent the game into extra time and the 19-year-old snatched the win late on to help them finish above Catalans in third spot.
Round 27 Results:
- Huddersfield Giants 16-14 Wakefield Trinity
- Wigan Warriors 48-4 Catalans Dragons
- Hull FC 4-36 Hull KR
- Leeds Rhinos 14-8 Castleford Tigers
- Salford Red Devils 14-32 Warrington Wolves
- St Helens 36-16 Toulouse
