Guy Porter crossed the whitewash in the fourth minute of added time in a dramatic contest – Fijian Nemani Nadolo and Argentinian Julián Montoya also dotted down for the two-times European Cup winners. George Ford added a further 13 points with the boot.

In response, Bristol notched a pair of tries through Fitz Harding and Ioan Lloyd, Callum Sheedy adding two conversions and four penalties for the 2020 EPCR Challenge Cup winners.

Elsewhere, Wasps – who are another Gallagher Premiership side competing in Pool B – overcame London Irish 38-30 in a thriller at the Coventry Building Society Arena.

Hooker Dan Frost scored a try in each half, while No.8 Alfie Barbeary and full-back Ali Crossdale also touched down. Jimmy Gopperth added 18 points in the kicking game.

Bath Rugby – who face an uphill battle in Pool A after an opening round defeat to Leinster Rugby - fell to a 40-20 loss at the hands of EPCR Challenge Cup contenders Gloucester Rugby.

Scrum-halves Ben Spencer and Oliver Fox were the try scorers on the afternoon for the 1998 European Cup winners. Fly-half Orlando Bailey kicked two conversions and two penalties in addition.

Leicester Tigers, who opened their Heineken Champions Cup campaign with back-to-back victories, maintained their 100% domestic record with a last-gasp 28-26 win over fellow Pool B contenders Bristol Bears.