Harlequins remain on course for top spot in Heineken Cup Pool Three after a comprehensive victory over Zebre in Parma. The Premiership pace-setters ran in eight tries to secure a winning bonus point.
Sam Smith scored a brace with Nick Easter, Matt Hopper, Rob Buchanan and Ben Botica also among the tries for Connor O'Shea's high fliers, who also managed two scrum penalty tries.
The most Zebre could manage on a bitterly cold day was a first-half breakaway try by Leonardo Sarto and a late consolation for Alberto Chillon.
With Biarritz losing to Connacht on Friday night, Quins' destiny now lies in their own hands and victory in next week's return against Zebre will effectively seal their passage through to the quarter-finals.
Harlequins were good value for their win and barely had to break sweat for some of their tries. The first came for Smith on 26 minutes, a routine dash for the corner after the home defence had been stretched on the back of a Maurie Fa'asavalu turnover.
Evans converted, adding to an earlier penalty, and already it looked as though the game was up for a desperately limited Zebre side, who failed to get out of their own half in the opening half hour. Things went from bad to worse for the hapless Italians when serial offender Mauro Bergamasco was sent to the sin-bin for a ruck offence.
With that it looked as though the floodgates would open, and Smith helped himself to a second try after linking superbly with Tom Williams. Again Evans converted to leave Quins 17-0 up and coasting.
It was Zebre who struck next though, Sarto racing away after one too many passes cost Quins as they looked for their third try.
It was shortlived joy for Zebre, who were back to square one within three minutes of the restart. Easter bagged Quins' third try after the visiting forwards wrestled the home pack into submission.
Danny Care, Matt Hopper and Mike Brown all went close to adding a fourth, but it was the forwards that made it, forcing a penalty try after dominating the home scrum.
They would do so again later in the half as Zebre went into meltdown, and sandwiched in between was a fine individual try by Hopper, who showed great footwork to outmanoeuvre the home defence.
He was eclipsed shortly after, however, by substitute prop Buchanan, who scored with practically his first touch after another irresistible attack by rampant Quins.
A late try by Chillon proved scant consolation for a disillusioned Zebre, and it was left to another substitute, Botica, to wrap up the scoring.
Harlequins director of rugby Conor O'Shea refused to get carried away with his side's demolition job, rejecting the notion that it sends out a message to the rest of Europe.
"It's one of those ones where you're damned if you do and damned if you don't," said the former Ireland international. "Of course there is ambition in the club, but people will write today's result off as irrelevant. And they are more than entitled to do just that.
"All we can do is to continue playing as a team, and make sure we are in control of our own destiny. When we lose games we don't get carried away, and it's the same when we win. It's about being in with a shout come April and May.
Easter was thrilled by his first try of the season. "It was about time for me," he said with a smile. "People had been getting on my case about it."
Zebre Trevisan (Ferrarini, 48), Venditti, Pratichetti, Garcia (Chillon, 69), Sarto, Orquera, Tebaldi, Aguero (Buso, 48), Festuccia (Redolfini, 48), Ryan (Perugini, 48), Geldenhuys, Sole (Caffini, 69), Cattina (Giazzon, 48), Bergamasco, van Schalkwyk.
Harlequins Brown (Dickson, 65), Williams, Hopper, Casson, Smith, Evans, Care (Buchanan, 65), Lambert (Marfo, 65), Gray (Botica, 65), Johnston, Kohn, Robson (Trayfoot, 70), Fa'asavalu, Wallace, Easter (capt).
Referee Neil Paterson (SRFU).
Tries: Smith (2), Easter, Penalty try (2), Hopper, Buchanan, Botica
Cons: Evans (6),Botica
Tries: Sarto, Chillon