Zebre were always likely to be facing a difficult day at Kingsholm and they were no match for in-form Gloucester, the Premiership side scoring 11 tries to stretch their winning run to seven matches and raise hopes of qualifying from Pool 3.
Last year’s runners-up ran riot in the first half, David Halaifonua scoring two of seven tries as they went into the break with a 45-0 advantage.
Thorley crossed twice in the space of 13 second-half minutes to complete his treble and added another late on, having claimed a double against the same opponents last weekend, with Serafin Bordoli and Valerio Bernabo going over for the visitors from Parma, who are rooted to the bottom without a point.
Gloucester sit three points behind leaders Pau following a day which saw Connacht move seven points clear at the top of Pool 5 with a 55-10 thumping of Brive at the Sportsground.
Healy proved to be too hot for the Top 14 strugglers to handle, touching down once in the first half and adding another three in the second.
Jack Carty was also outstanding, helping himself to 20 points from the tee and a try as Connacht maintained their 100 per cent record.
Lyon moved from the bottom of Pool 2 to the summit with a 22-11 victory over Toulouse at Matmut Stade de Gerland and defending champions Stade Francais enhanced their chances of qualifying from Pool 4 with a 26-20 success at London Irish.
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