FORMER Thornbury Broncos duo Billy and Mako Vunipola will miss out on a European Champions Cup and Aviva Premiership double this season.

Exeter ended the hopes of Saracens, the Vunipola brothers’ club, of a second successive European and domestic double in dramatic fashion at Sandy Park.

Replacement back-row forward Sam Simmonds scored an 80th-minute try to secure an 18-16 home triumph and halt Saracens' reign as Aviva Premiership champions.

Seven days after lifting the European Champions Cup by beating Clermont Auvergne, Saracens looked to have again dug deep as replacement wing Mike Ellery's 76th-minute touchdown appeared to floor the Chiefs.

But Devon's finest, unbeaten in the Premiership since October, somehow clawed out a narrow victory following an earlier Jack Nowell try and eight points from skipper Gareth Steenson.

Saracens, conquerors of Exeter in last season's Premiership Twickenham showpiece, had hoped to emulate Leicester 15 years ago by retaining European and domestic titles, but the Chiefs had other ideas.

Wing Chris Wyles scored a 57th-minute try for Saracens, with captain Owen Farrell kicking two penalties, yet Exeter had just enough in the tank to keep alive hopes of being crowned English champions for the first time in their 146-year history.