Louis Rees-Zammit marked his British and Irish Lions selection with two tries as Gloucester beat lacklustre Northampton 31-7 in the Premiership.
The winger capped a fine 14th-minute move in a poor first half that saw fellow Welsh Lion Dan Biggar fail a head injury assessment.
Ed Slater and Jack Singleton increased Gloucester's lead after half-time.
Rees-Zammit's second try sealed the bonus point before Henry Taylor got a consolation try for Saints.
The result - Gloucester's biggest win of the season - sees them stay 10th in the Premiership as fifth-placed Northampton's play-off hopes took a blow.
With Lions boss Warren Gatland in the stands Billy Twelvetrees' early penalty put Gloucester ahead before Rees-Zammit's try ended the best move of the first 40 minutes. Mark Atkinson's no-look pass allowed Santiago Carreras to break into open ground before passing to Rees-Zammit who went over in the right corner.
There were worries when Biggar's head clashed with Twelvetrees' shoulder as the pair dived for a loose ball - the Northampton fly-half failed a head injury assessment although he did walk from the field under his own steam.
Slater went in from 15 metres after George Furbank's loose kick was gathered by Jordy Reid and Twelvetrees added a second penalty soon after.
Another Saints penalty set up the short-range line-out for Gloucester's third as Singleton was forced over before Rees-Zammit used his renowned pace to pounce on a Saints fumble as he touched down Willi Heinz's box kick with 20 minutes to go.
A fracas in the aftermath of the try saw Carreras and Saints' Piers Francis sin-binned and Gloucester were further reduced soon after when Tom Seabrook deliberately knocked on.
Gloucester's defence was impressive throughout, and with a man down they did well to stop Tommy Freeman going over with 12 minutes left before Taylor snuck in from the back of a ruck inside the final 10 minutes as Saints avoided a first shutout since 2005.
Northampton: Furbank; Proctor, Hutchinson, Francis, Freeman; Biggar, James; Waller (co-capt), Matavesi, Hill, Ribbans, Ratuniyarawa, Wood, Ludlam (co-capt), Harrison.
Replacements: Fish, Auterac, Painter, Moon, Adendorff, Taylor, Dingwall, Naiyaravoro.
Gloucester: Moyle; Rees-Zammit, Kveseladze, Atkinson, Carreras; Twelvetrees, Chapman; Rapava-Ruskin, Singleton, Balmain, Slater, Alemanno, Reid, Ludlow (captain), Ackermann.
Replacements: Socino, Ford-Robinson, O'Connor, Morgan, Clement, Heinz, Barton, Seabrook.
Referee: Ian Tempest