If there was an image to sum up the Investec Champions Cup knockout rounds, it came with the clock nearly three minutes into the red at a scorching Stade Felix-Mayol on Saturday afternoon. As Marcel Theunissen, the replacement back rower, picked and ploughed for the line, players from both the Stormers and Toulon threw their arms aloft like heavyweight fighters as each claimed victory; after a long deliberation in conjunction with his television match official, referee Christophe Ridley stuck with an on-field call of held up.

It sent the French side through, the South Africans away with plenty to ponder – why was there no drop goal? Why, with a two-man advantage, did they keep things so narrow? – and the rest of us to marvel at how wonderful this competition can be. As detailed time and time again in these pages, this version of the Champions Cup is riddled with issues and a pale imitation of what it used to be but for the delivery of drama, and for an intensity of contest, it stands consistently above any club competition. The round-of-16 winners may have been predictably home-side heavy but few would have felt short-changed in terms of entertainment.

Certainly, those paying fair whack at The Rec would have still felt they received value for money. Bath’s 31-22 win over Saracens was a cracking, crackling cup tie – before the game, the matchday announcer found a travelling family of Norwegian tourists for whom this was a first taste of rugby union. They will surely spread the gospel; perhaps we can expert more visitors over from Oslo once James Dyson and Bruce Craig build their new stadium.

One should not underestimate the significance of Saturday’s success for Bath. Before the game, a few fans were guilty of overlooking the challenge that Saracens would pose, talking already of the prospect of Northampton, victors against Castres on Friday night, in a quarter-final to come. But Bath had not hosted a knockout tie in this competition since 2002; it looked for a long time like they might not earn a second.

But they did, and in the process served a reminder of the strength in depth that makes them Champions Cup contenders. South African interest in this competition may have ended by narrow defeats for the Stormers and Bulls, yet it was still a Springbok who perhaps had the most pivotal impact of the round. “It’s quite handy having Thomas du Toit coming off the bench, isn’t it?” smirked Saracens boss Mark McCall, whose side had been in control at the set-piece until the replacement tighthead’s arrival.

The first engagement after his introduction saw Beno Obano, on the loosehead, sent to the sin bin, but Bath were dominant thereafter. Du Toit swung both scrum and game his side’s way, enabling them to overcome on a day where they did not find attacking fluency or their usual red-zone efficiency.

Johann van Graan has an embarrassment of riches at the position, with the injured Will Stuart and starter Archie Griffin both Test tightheads, too, and youngster Vilikesa Sela an England international in waiting. But it is his 30-year-old South African that Van Graan goes to in the big moments – it is he, rather than Finn Russell, that has been their best signing in recent years.

“I thought Thomas was fantastic in that second half,” the Bath director of rugby said. “In my view, he’s currently one of the best players in the whole world. He showed that again today – he was absolutely phenomenal in the scrum, in defence and in attack. That’s why you build a squad. You call on 23 guys on a weekend, and all credit to the players.”

Du Toit’s impact underlining just how important this season may be for Bath. It is difficult for Prem clubs to mix it with the French big boys and Leinster when it comes to squad depth in this competition – Northampton’s appearance in the Champions Cup final last year was an exception that proved the rule, given that the Saints all-but-sacrificed their domestic campaign to prioritise a European run. Bath, conversely, appear equipped to compete on both fronts – though perhaps not for long.

Come the end of the season, Du Toit is headed home having agreed a deal to re-sign for the Sharks. It is not just he moving on – No 8 Alfie Barbeary is bound for Saracens, where he has the sizeable shoes of Tom Willis to fill, with Francois van Wyk, Will Butt and Ethan Staddon other vital depth pieces headed elsewhere. The re-signing of Russell, retention of several other key figures and continued strength of the pathway will keep Bath competitive but it is fair to suggest that this may be the strongest squad they will possess in this era.

Saracens have played Toulouse and Glasgow as well this season and fly half Fergus Burke believes Bath are as good as any side. “They are so physical up front,” the Scotland international said. “They’ve got one of the best 10s in the world driving them around, and he’s got eight forwards starting and six on the bench that are genuinely massive. They give him the platform to pull the strings. I can see them going deep in this competition. They are one of the best teams in Europe without a doubt, and I hope they go all the way.”

A six-day turnaround for Bath against Northampton, who won at the Rec just after Christmas, will pit the two best sides in England against one another; another likely last-eight tie between Toulouse and Bordeaux-Begles will see the Top 14’s top two test their mettle. Another captivating Champions Cup weekend is in store.