Northampton beat Cardiff at Franklin's Gardens in the opening round of the Champions Cup, becoming the only English team to record a win in the first round of the competition. The Group Four match was tense, with the hosts leading 14-0 at half-time.

Northampton scored four tries. James Pater and Toby Thame scored tries in difficult conditions, while George Hendy and Fraser Dingwall also crossed the line. Cardiff were led by Harri Millard and Mason Grady, who scored tries, and in the final quarter of the match Cardiff closed the gap to two points. Northampton ultimately won without a bonus point.

Saints were quarter-finalists last season, and in their first three title defence matches in the Premiership, they scored 24 tries, including 11 tries against Bath in their last match at Franklin's Gardens. Cardiff returned to the elite tier of European competition after two seasons in the Challenge Cup, but had a five-day break before their United Rugby Championship match against the Sharks at Cardiff Arms Park. Several influential Cardiff players were rested, and Taulupe Faletau and Josh Adams made their first appearances of the season after injuries. Northampton made changes ahead of their match against Leicester on Saturday.

Full-back Pater opened the scoring for Saints with a supported run, and centre Thame broke through after 20 minutes. Northampton number eight Callum Chick dropped the ball while heading towards the line, as did Cardiff lock Tom Manz. Slippery conditions led to a 14-0 half-time score. Cardiff centre Millard broke the line in the 22 early in the second half, and the score was 14-12 at the hour mark. Saints fly-half Anthony Belleau was yellow-carded for a breakdown infringement, and the ball was passed to the right from Jarrod Evans for Grady's try. Hendy juggled the ball for a try converted by Pater, and Northampton's wing caught up with Adams when a try seemed certain. Dingwall ran in in the 78th minute, but the hosts failed to find the fifth try needed for five points.

Saints travel to Stade Francaise in December, return to France in January to play Montpellier, and finish the group stage at home against Bulls. Cardiff host Bath in December, travel to Stade Francaise in January, and host Montpellier. The match was refereed by Jeremy Rozier from France, with Thomas Charabas and Cyrille Boulay as assistant referees, and Julien Castaignede as TMO. Belleau received a yellow card in the 60th minute.