Bristol ran in seven tries at Ashton Gate as they beat French side Pau 41-14 to register their first win in European competition for eight years.
Fullback Jack Wallace, wing Tom Varndell, fly-half Billy Searle and inside centre Luke Arscott all touched down in the first half to give Bristol an unassailable 22-7 half-time lead in the lone European Challenge Cup clash on Sunday.
Two tries from substitute Chris Brooker and another from outside centre Thretton Palamo in the second period sealed Bristol's second win in all competitions this season.
Bristol, bottom of the Aviva Premiership after losing all 10 of their games so far, had only won once before this season, against Sale in the Anglo-Welsh Cup in November, but they were too strong for Pau, who they leapfrog at the bottom of Pool Four.
Two conversions from Bristol number 10 Searle and another from substitute Adrian Jarvis completed the scoring for the west country side, while Pau scored two tries through wing Watisoni Votu and substitute Thibault Daubagna.
Bristol's only other previous win in European competition was in 2009 against French side Montpellier in the Challenge Cup.
Cardiff Blues stamped their authority on Challenge Cup Pool Four after a 28-3 win over closest rivals Bath in one of five games on Saturday.
Fullback Matthew Morgan, wing Alex Cuthbert and replacement Scott Andrews scored tries for the Guinness PRO12 side, with Steven Shingler adding two conversions and three penalties.
Tom Homer's 12th-minute penalty provided the only points of the day for Bath, as pool leaders Cardiff extended their advantage to five points in the standings.
In Pool Three, Worcester defeated Newport Gwent Dragons 33-20 to leapfrog them into third place, despite being temporarily being reduced to 13 men in the first half.
Sam Betty and Christian Scotland-Williamson were both shown yellow cards within the first 20 minutes after Angus O'Brien gave the Dragons a 6-0 lead thanks to a drop goal and penalty.
However, a try from Val Rapava Ruskin, converted by Connor Braid, on the stroke of half-time gave Worcester a 7-6 lead at the break.
Dean Hammond and two penalty tries, both converted by Braid, saw Worcester pull clear and claim a bonus point while Newport had Leon Brown in the sin-bin.
Max Stelling added Worcester's fifth try in the 72nd minute before a late rally from the visitors saw Ashton Hewitt score two converted tries in two minutes, but it was too little too late for the Welsh province.
French Top 14 side Brive defeated Russian club Enisei-STM 43-8 after tries from Nicolas Bezy, Guillaume Namy, Guillaume Ribes and Benito Masilevu to go top of the pool on points difference.
Fullback Gaetan Germain added 21 points with his boot and Bezy also chipped in with a conversion, while Anton Rudoi's try and a Igor Kuashov penalty were the only scores for the hosts.
Harlequins thrashed Romanian outfit Timisoara Saracens 42-3 after running in six unanswered tries.
Dave Ward, George Merrick, Aaron Morris, Charlie Walker (two) and Joe Marchant all crossed the whitewash, with Ruaridh Jackson slotting all six conversions.
Timisoara's points came thanks to a penalty by scrum-half Valentin Calafeteanu.
Edinburgh beat Stade Francais 28-23 in Pool Five, despite the 55th-minute dismissal of centre Phil Burleigh for an unprovoked slap in the face of prop Pascal Pape.
Damien Hoyland, Ben Toolis and Sam Hidalgo-Clyne all scored tries for the Guinness PRO12 side, with fly-half Duncan Weir adding 13 points in the form of three penalties and two conversions.
Stade's tries were scored by centre Waisea Nayacalevu and flanker Sekou Macalou, with Morne Steyn kicking two penalties and conversions and a drop goal.
The result saw Edinburgh move two points clear of Harlequins at the top of the pool, while Stade remained in third, six points clear of winless Timisoara.