The Londoners now need just one point in the final two rounds to guarantee their place in the last eight of the Heineken Cup.

Similar to last week's performance, Harlequins had to be patient in the first half to grind down the spirited Italian side. With a try from Tom Casson followed by a penalty try in the first half, the flood gates opened as scores from Ben Botica, Tom Guest, Sam Smith, Danny Care and Karl Dickson completed the victory.

It was a scrappy opening for Harlequins, the Londoners were creative in attack, but lacked the finishing touch on occasions.

Nick Evans opened the scoring with a penalty on three minutes and was converting Casson's try a few minutes later.

Harlequins had the lion's share of possession and territory and after working into the 22, Evans chipped over the on rushing defence. The ball rolled over the line and Casson scored under the posts. The score was a just reward for the centre, who had made three promising breaks in the opening minutes.

When Ugo Monye stole an up and under from the fingertips of Ruggero Trevisan and won a penalty, Danny Care's quick tap penalty set the Stoop alight.

The nippy scrum-half mirrored Evans and chipped the ball over the line. Care was taken down which allowed the Italians to clear their lines from a 22 drop out.

Harlequins continued to play with a creative mind set, but were turned over on a number of occasions. The visitors had their first points opportunity on 25 minutes however Luciano Orquera's shot at goal went wide.

The fly-half made up for his error just two minutes later. Cutting through the defence from a scrum on half way, the Italian international was brought down five metres from the line. After quickly recycling possession, the full-back Trevisan scored. Orquera's conversion attempt missed in what was Zebre's only contribution to the scoreboard.

Evans added a penalty on the half hour mark and when Harlequins continued to pressurise Zebre, Daniel Halangahu was shown yellow for slowing the ball down.

Choosing the scrummaging option from the penalty, Harlequins' dominance resulted in a penalty try when the Zebre front row collapsed, with the easiest conversion Evans extended the lead to 20-5.

Harlequins welcomed Ben Botica in the second half and the centre made a fantastic impact scoring after just two minutes. When Giovanbattista Venditti was forced into touch from a Smith chip and chase, Harlequins took a quick lineout. Care received the ball and fired a pass to Botica in midfield. The Kiwi broke the initial line of defence and despite being tackled five metres short, he scrambled over.

Halangahu returned from the sin bin, but four minutes later, the visitors were again reduced when replacement Gonzalo Garcia stole the ball from an offside position.

Kicking to the corner from the penalty, the Harlequins forwards set up a driving maul, Danny Care passed to Tom Guest on the blindside who drove over the line.

Guest then made another powerful run after picking from the back of a scrum on half way, working into the 22 Harlequins were awarded a penalty five metres from the line. Opting for a scrum the ball found Jordan Turner-Hall who came within inches of the line, quickly spinning it wide the ball found Smith who crossed in the corner.

The winger played a major part in Care's try eight minutes later. Stealing a lineout in their own half, Smith broke the line. With a two on one, the winger drew Venditti and passed to Care who ran 40 metres to score.

Harlequins completed their scoring through Dickson. The home side were awarded a penalty in the Zebre 22 and a quick tap from the scrum-half allowed him to cross. Evans converted and Harlequins won 53-5.