Ashton's final Franklin's Gardens bow
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 Aviva Premiership play-off semi-finals with a 42-14 win.
Saracens-bound Ashton took only five minutes to mark his final home appearance with a try before picking up an injury 14 minutes later.
England full-back Ben Foden, winger Paul Diggin and replacement forwards Teimana Harrison and Alex Waller scored Northampton's other tries with fly-half Stephen Myler kicking 10 points and his replacement Ryan Lamb booting seven.
Worcester replied with tries from left-wing Josh Drauniniu and number eight Kai Horstmann, both converted by fly-half Danny Gray.
The victory clinched fourth place in the Premiership table for Saints as they joined Harlequins, Leicester and Saracens in the play-offs.
The home side, refusing to take a safety approach, showed their ambition by passing up the chance of a kickable shot at goal after their powerful scrum forced the backpedalling Warriors pack to concede a penalty.
They won the resulting lineout and displayed slick handling to move the ball left to right across the pitch and all the way back before striking.
Flanker James Craig's pass found Foden who turned the ball back inside for the supporting Ashton to score, displaying his trademark swallow dive for the final time in a Northampton shirt at Franklin's Gardens.
The Warriors, who had defended stoutly, were temporarily reduced to 14 men when skipper Shaun Perry was yellow-carded three minutes from half-time for hands in the ruck in front of his own posts. The departure of the former England scrum-half turned the game Northampton's way and they took full advantage.
Worcester conceded 13 points while Perry was binned and the captain did not re-appear when his 10 minutes was up as the Warriors sent on Johnny Arr as his replacement.