Saracens got revenge for their loss to Northampton in last season's Premiership Rugby Cup final with a 54-28 win over the holders at Franklin's Gardens.

Nick Tompkins' hat-trick of tries was the highlights for the visitors, with Matt Gallagher, Rotimi Segun, replacement Ben Spencer and Manu Vunipola also crossing.

Saracens led 23-21 at the turnaround and took the game away from their Pool A rivals with three tries in the final quarter.

Vunipola converted four of the tries, with Thomas Whiteley kicking three penalties and a conversion of his own.

The only blemish for the visitors was a red card for Charlie Watson inside the final quarter, after he appeared to kick out at Andy Symons.

Symons claimed two tries for Northampton, the others coming from Henry Taylor and David Ribbans. All were converted by James Grayson.