Harlequins ran seven tries past Zebre at the Stoop for a comfortable 53-5 bonus-point victory in the Heineken Cup on Saturday.
The result effectively secures top spot in Pool 3 for the English champions, who are now ten points clear of Biarritz with two games remaining.
Harlequins exploded into action in the second half as they hammered Zebre for the second time in as many weeks.
After racking up over 50 points in Italy last weekend, the home side might have been expecting an easy ride in front of their own fans but they were made to work hard in the first half.
A Nick Evans penalty and a try from young centre Tom Casson did give Quins an early lead but the visitors were determined not to go down without a fight and a great run from Luciano Orquera set up a try for Ruggero Trevisan to half the deficit before the half-hour mark.
The game became a lot more comfortable for the hosts just before half-time though as another three points from the boot of Evans was followed by a yellow card for Daniel Halangahu and a penalty try after several infringements in the scrum.
Replacement Ben Botica had only been on the field two minutes when he opened the scoring in the second half and, when Gonzalo Garcia was sinbinned soon afterwards, it looked like another long afternoon was on the cards for Zebre.
And so it proved as Nick Easter finished off a great drive from the Harlequins pack to seal the bonus point and winger Sam Smith added a fifth before the hour mark.
Quins then made a host of changes but the visitors' spirit was broken and they again surpassed the 50-point mark as scrum-halves Danny Care and Karl Dickson made it seven tries either side of Zebre's third yellow card of the match for Filippo Ferrarini.
Tries: Casson, Penalty try, Botica, Easter, Smith, Care, Dickson
Cons: Evans 6
Pens: Evans 2
Yellow cards: Halangahu, Gacia, Ferrarini
Harlequins: 15 Mike Brown, 14 Ugo Monye, 13 Matt Hopper, 12 Tom Casson, 11 Sam Smith, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (c), 6 Tom Guest, 5 George Robson, 4 Charlie Matthews, 3 Will Collier, 2 Joe Gray, 1 Mark Lambert.
Replacements: 16 Rob Buchanan, 17 Darryl Marfo, 18 Kyle Sinckler, 19 Sam Twomey, 20 Luke Wallace, 21 Karl Dickson, 22 Ben Botica, 23 Jordan Turner-Hall.
Zebre: 15 Ruggero Trevisan, 14 Giovanbattista Venditti, 13 Samuele Pace, 12 Daniel Halangahu, 11 Leonardo Sarto, 10 Luciano Orquera, 9 Alberto Chillon, 8 Dries van Schalkwyk, 7 Filippo Ferrarini, 6 Nicola Cattina, 5 Josh Sole, 4 Mike Van Vuren, 3 Luca Redolfini, 2 Davide Giazzon, 1 Andrea de Marchi.
Replacements: 16 Andrea Manici, 17 Carlo Fazzari, 18 Salvatore Perugini, 19 Nicola Belardo, 20 Filippo Cristiano, 21 Luca Martinelli, 22 Matteo Pratichetti, 23 Gonzalo Garcia.