Newcastle face relegation from the Aviva Premiership despite their crunch basement battle against fellow strugglers Wasps ending with a hard-earned 14-10 victory.
The Falcons finished bottom by a point following a 22-game regular league season that saw them win just six matches.
They needed a bonus-point triumph over 11th-placed Wasps - and also deny their opponents a losing one in the process - but that fanciful script never seriously looked like unfolding at a packed Adams Park.
England internationals Danny Care and Mike Brown went over Harlequins secured top spot with a 24-10 triumph over Sale in the Sharks' last ever game at Edgeley Park.
Billy Twelvetrees showed what Leicester will miss next season when he helped the Tigers book a home semi-final with a comfortable 28-3 win over Bath in their last home game of the season.
Saracens gave a convincing second-half performance to run out comfortable 40-22 winners over Exeter at Vicarage Road.
The home side trailed 10-9 at the interval but two tries early in the second half gave the hosts the impetus they needed.
Chris Ashton's Franklin's Gardens farewell lasted only 19 minutes, but it was long enough for the England winger to score the try which set Northampton on the way to the play-off semi-finals with a 42-14 win.
London Irish gave England-bound attack coach Mike Catt the perfect send-off with a 52-18 win over Gloucester in a Madejski Stadium contest marred by the sendings off of Jim Hamilton and David Paice.
The game was effectively over by half-time as tries from Darren Allinson, Sailosi Tagicakibau and Jonathan Joseph, plus a 19-point haul from Tom Homer, put Irish 34-11 ahead. Homer kicked another penalty while substitute Marland Yarde (2) and the departing Delon Armitage added further tries to complete the rout.