Chris Ashton's try propelled Saracens to a 10-3 victory over Toulon at Allianz Park in a result that sees both teams qualify for the Champions Cup knockout phase.

Ashton broke the deadlock by crossing in the 60th minute to secure the reigning champions a home quarter-final, while Leigh Halfpenny's penalty posted the crucial bonus point that ensures the French heavyweights also progress.

It was a slick finish from the former England wing, who was also involved in the build up to the only try of the afternoon but was assisted by some feeble tackling from Ma'a Nonu and Matt Giteau.

Points were at a premium in a full-blooded heavyweight Pool Three showdown that produced a series of furious collisions and thunderous hits, the best of which saw Michael Rhodes halt Giteau as the line beckoned.

Halfpenny kicked Toulon's only three points (Getty)

The closing minutes served up a grandstand finish as Saracens held out two five-metre scrums, Will Skelton brought down Samu Manoa on the whitewash and Halfpenny missed a second penalty attempt.

The outcome suited both teams, however, and they could meet again in the quarter-finals in a scenario that would see Mike Ford's men return to Allianz Park.

Toulon somehow failed to take the lead in the eighth minute when an all-too casual Josua Tuisova dropped the ball over the line when all he had to do was touch down, wasting the good work of Bryan Habana and Nonu that set him up.

The half hour mark passed and neither team had registered on the scoreboard, but it was a lively if edgy opening 30 minutes of hard-fought rugby.

Toulon were trimmed to 14 men when captain Duane Vermeulen was sent to the sin-bin for a high tackle on Nick Tompkins as the inside centre stepped inside him and the deadlock was broken when Owen Farrell landed the subsequent penalty.

Joshua Tuisova dropped the ball as he went to touch down for Toulon (Getty)

Tompkins showed no lingering after-affects from the swinging arm as he threaded through several tackles, launching an attack that ended when Marcelo Bosch was held up over the line.

Rhodes pounced for a turnover close to Saracens' line, initiating a series of drives and a chip ahead from Ashton that pinned the French giants close to their own whitewash, but the attack petered out.

Tuisova shoved off Farrell and Jamie George as he rampaged across field but the phase of the match ended with Toulon being penalised at a scrum just as they sought to turn the screw.

Saracens refreshed their front five through the arrival of Schalk Brits, Juan Figallo and Skelton from the bench and now small but discernable holes began to appear in the visiting defence.

Figallo, with the assistance of Maro Itoje, forced a penalty and while Farrell missed the posts, daylight finally opened between the rivals in the 60th minute.

Ashton ran straight and Tompkins continued the move until Toulon were left scrambling just yards from the line, but Nonu and Giteau should still have stopped Ashton as he ran between the two greats to finish.

Halfpenny landed a long range penalty, but the kick was quickly forgotten as Alex Lozowski's head shook following a ferocious tackle from Bastareaud.