Richard Haughton scored a treble as Saracens produced a 10-try 71-7 victory against Italian side Viadana at Vicarage Road.

Sarries number 10 Glen Jackson was once again the star of the show, scoring 25 points, which included a second-half touchdown, as Alan Gaffney's men ran riot.

Saracens have made a bright start to Pool Four, with a bonus point win over Glasgow and a narrow bonus point loss to Biarritz in the opening weeks.

And with All Blacks lock Chris Jack and South African full-back Brent Russell both making their debuts, they took another giant stride towards quarter-final qualification against Viadana.

The Italians were hunting their first away win in Europe's premier competition but against a Sarries side high in confidence after qualifying for last week's EDF Energy Cup semi-finals - Viadana had a mountain to climb at the break as Gaffney's men led 36-0.

The home side dominated from the off, number 10 Jackson turned down a tricky three points in the windy conditions and kicked for the corner early on - and from the resulting lineout a powerful driving maul saw Fijian flanker Sakiusa Matadigo touch down for a score on his debut.

Jackson's boot was dictating the play but it was his slick handling which set up Sarries' second score in the 15th minute. From a lineout Jackson found winger Haughton who slide in at the corner.

Viadana indiscipline began to cost them and when second row Dion Waller killed the ball in front of the posts - Jackson kicked a comfortable penalty as Saracens took a commanding lead.

With a penalty for offside - Jackson again went for the corner and in a carbon copy of the first try veteran England international Richard Hill touched down - with Jackson again converting.

On the stroke of half-time Sarries secured a bonus point with two quick tries. First Haughton finished off a slick move to go in for his second.

His effort was quickly followed by winger Kameli Ratuvou running unopposed from his own half to touch down under the posts for try number five.

Viadana's indiscipline continued in the second half and in the opening minutes they were reduced to 14 men as second row Waller was sin-binned for stamping.

From the resulting penalty Jackson again opted for the lineout, which inevitably produced the same result - this time replacement prop Census Johnston burrowed over.

Viadana finally got some points on the board when stand-off Calvin Howarth intercepted an ambitious Andy Farrell pass to run 80 yards and touch down under the posts.

Haughton completed his hat-trick - capitalising on a defensive slip to collect Russell's kick and slide in at the corner, before a slick handling love saw Jackson cross from close range before converting to bring up Sarries' half-century.

Ratuvou then claimed his second of the afternoon - finishing off a flowing move which began with a scrum in their own-half.

Full-back Russell was then denied a try on his debut as he collected a dropped pass before touching down but the referee adjudged the ball had gone forward.

Sarries continued to show good handling skills and Ratuvou and replacement Adam Powell were unlucky not to convert scoring opportunities.

But the home side wrapped up the points when they were awarded a penalty try in the final minute as the Viadana scrum collapsed one too many times - Jackson converted to add the final points for Sarries.