There are big games and then there are contests which define entire campaigns. And when the moment came it was Bath who just had enough turbo thrust to propel themselves into the Champions Cup semi-finals for the first time in 20 years. There is little to separate the two best teams in England and this was another endlessly compelling battle of wits and wills, ultimately settled by a 76th-minute try by Bath’s replacement forward Ted Hill.

Plenty of work still has to be done to reach the final in Bilbao next month with Johann van Graan’s side now facing the winners of Sunday’s mouthwatering all-French tie between Bordeaux and Toulouse. This was a truly sensational hors d’oeuvre, though, with nine tries in the first half alone. Gone are the days of tiptoeing into knockout matches and hoping to edge it 9-6.

It was a humdinger from start to finish. From 28-7 down after 22 minutes, Bath came roaring back to trail by only 38-33 with 20 minutes left, with their opponents temporarily down to 14 players. From there their renowned forward strength tipped the scales, with player-of-the-match Alfie Barbeary and Thomas du Toit among the key figures.

It was still mightily close and a grand advert for the English club game. If there is to be a sequel in this year’s Prem final few neutrals will complain, with even Van Graan marvelling at his side’s dramatic fightback. “I have been in rugby for a long time and this ranks as one of the best I have been involved in,” said the South African. “That was some game of rugby. We don’t know how to give up.”

Ultimately it was a triumph for both coaching teams. While Bath’s bench impact in the final quarter is well known and was evident again, Saints’ attack was wonderfully good at times. The visitors were always in the contest with Henry Pollock prominent throughout until he was sent to the sin-bin, to much local delight, with seven minutes left. “Not wishing to sound like Arsène Wenger but I haven’t looked at it again”, said Phil Dowson, Saints’ director of rugby. “The referee’s not going to change his decision now. It was obviously a good game of rugby but it’s frustrating to be on the wrong side of it.”

The visitors could not have done much more, rattling up five slick tries in the first half-hour alone. Pollock had them on the board after just two minutes, marking the moment with a slam dunk celebration right in front of the Bath owners’ corporate box. By then Miles Reid was already in the sin-bin for cynically trying to slow down the fizzing visitors’ ruck ball and the fast-moving tone had already been set.

Next up was a lovely one-handed midfield tip on by Archie McParland which allowed Fin Smith and Tommy Freeman to send Fraser Dingwall away for another rip-roaring score. When they attack with such surgical precision Saints are a complete joy to watch. And after a much-needed close-range response by Tom Dunn, the Rec was about to go quiet again. Once again the chance was engineered by some brilliant offloading, creating more than enough time and space for big Tom Lockett to rumble over in the right corner.

A little bit of luck also flowed Northampton’s way, a deflected kick ending up in the arms of Rory Hutchinson, who immediately launched another sharp counterattack before a splendid inside ball out of the tackle set up a fourth Saints try, this time for Josh Kemeny.

Bath urgently needed some kind of response and found one when Finn Russell dribbled a loose ball into space and finished with aplomb, only for the newly married Ollie Sleightholme to barge past several defenders and register a try on his 100th club appearance. At 35-14 down, Bath had no other option but to go for broke, helped by the arrival off the bench of the energetic Barbeary.

Two tries inside seven minutes towards the end of the half from Henry Arundell and Francois van Wyk gave the scoreboard a much healthier look only for a Smith penalty early in the second half to stretch Northampton’s lead to 12 points. It took the sending to the sin-bin of JJ van der Mescht and, subsequently, Pollock to prise open the door with Kepu Tuipulotu and then Hill barging through it to send the ecstatic Bath faithful into orbit. If every game between now and the end of the season is as good as this, everyone will be hoarse by June.