Former Heineken Cup winners Northampton began at a hectic pace, but it was actually Castres who scored first when Samoan lock Josefa Tekori forced his way over from a close-in scrum after 22 minutes.

Bernard's missed conversion was sandwiched between two wayward penalty attempts, and the hosts took advantage to level the scores when veteran Kiwi winger Bruce Reihana crossed on 32 minutes. But, like Bernard, Reihana was also struggling with his kicking radar and failed to add the extras. Indeed, the New Zealander was taken off kicking duties after that as he had already missed with three earlier penalty attempts.

Castres' Australian fly-half Cameron McIntyre put the French side back in the lead with his 34th-minute drop-goal, but the visitors were down to 14 shortly after when hooker Mathieu Bonello was sin-binned for killing the ball.

The Saints poured forward trying to take advantage before the break, but an injury time penalty was again squandered when Shane Geraghty scuffed his attempt badly.

The home side didn't have long to wait before claiming the lead, however, as Ben Foden touched down for the second try of the match just 35 seconds after the resumption. This time Geraghty did get it right, and the conversion put Saints 12-8 ahead.

Bernard then missed yet another penalty attempt before finally getting it right - at the fourth attempt - to narrow the gap back to just one point with 20 minutes to play.

Geraghty and Bernard traded a further success each over the next 10 minutes, leaving just that solitary point between the two sides before replacement fly-half Stephen Myler finally sealed Northampton's win with a 78th-minute penalty.

Castres will certainly rue their missed kicks, especially after dominating for long periods of the second half, but coaches Laurent Labit and Travers said beforehand they were targetting a defensive bonus, so the return home shouldn't be too unhappy.

In the night's two other Heineken Cup matches Glasgow Warriors beat Newport Gwent Dragons 21-13 in Pool 6, while Ulster eased past Aironi Rugby 30-6 in Pool 4. 

Full Heineken Cup preview