The English Champions now need just a point from next week’s trip to Benetton Treviso after a Ben Spncer try and five Owen Farrell penalties saw them edge past the twice beaten finalists at Vicarage Road.

Saracens dominated territory and possession but Dimitri Yachvilli ensured it was an uncomfortable last 20 minutes for Mark McCall’s men as his boot and his own converted try kept the game in the balance until the death.

Sarries led 14-6 at the break thanks to a trio of three pointers from new England squad member Farrell and Spencer’s well-taken 18th-minute score.

The young scrum-half added to his growing reputation by darting over from 10 metres out after Farrell’s hack ahead in midfield. David Strettle and Ernst Joubert combined to take Sarries to within 10 metres of the line before Spencer snuck through three tackles for a fine score.

Yachvili followed Diego Dominguez, Ronan O’Gara and Stephen Jones in passing 600 Heineken Cup points with his first penalty on nine minutes but he could only add one more before half-time and missed a relatively straightforward effort that would have narrowed the gap to four just before the interval.

The third quarter then looked set to end scoreless before an error from Sarries replacement Peter Stringer gifted the visitors seven points.

The veteran Irish international – who scored Munster’s winning try in the 2006 Heineken Cup Final against Biarritz – saw his box kick charged down by Yachvili just minutes after coming on for Spencer.

Biarritz’ long-standing talisman converted and suddenly the gap was just a single point at 14-13 on the hour mark.

Farrell kicked Sarries four points clear two minutes later but Yachvill struck again on 68 minutes to ensure a nervous ending in North London.

It was Sarries and man of the moment Farrell who had the last laugh, however, as the 20-year-old kept his cool to land a 40 metre penalty that left Biarritz chasing a try with five minutes remaining.