For Ulster, the nerves were settled nice and early.

Ulster needed to step up - and they did.

It took just four minutes for Nick Timoney to ignite the home fans with a tension-easing try.

Ulster have struggled to hold on to leads this season, but there would be no wobble here as Timoney's score set the 1999 winners on their way to an important Investec Champions Cup win.

After three successive losses, and the memory of a bitterly disappointing second-half showing in their Pool 2 opener at Bath last week still fresh for Ulster, there was a palpable sense of anxiety in Belfast as kick-off beckoned.

And with good reason. While Racing lost their opener at home to Harlequins, the consensus was that the Top 14 leaders - who boasted South Africa's two-time World Cup-winning captain Siya Kolisi in their ranks - would provide another robust examination of Ulster's European credentials.

It didn't quite work out that way, and while Stuart Lancaster's side punctured the Ulster defence three times, the hosts produced their most incisive performance in recent memory to give their season a timely shot in the arm.

"[It was] definitely our best [performance] for a while," said Ulster head coach McFarland.

"I was speaking to a number of senior players in the week and they had a feel that we're bubbling away.

"The opportunities that we've created, particularly with the ball in the last two games against Bath and Edinburgh left us feeling that we left a lot out on the field, but also confident that the foundations of what we're trying to put together are there."

That confidence was clearly not misplaced. Undeterred by disjointed and error-strewn performances in recent weeks, Ulster were at their free-flowing best at times against Racing, moving the ball with speed and purpose and serving up thrilling flashes of what they are capable of when the main facets of their attack click into place.

Refusing to let Racing settle was key with the first two tries of the night - from Timoney and the brilliant Stuart McCloskey - scored after opportunistic tap penalties either side of a Nolann Le Garrec try that was created Antoine Gibert's superb crossfield pass.

Ulster looked vulnerable when Racing screamed forward at pace, but after Matty Rea put the hosts 21-5 up at the break and Timoney clinched the bonus point with another try coming off a tap and go, the deficit proved insurmountable for the French side.

Earlier in the week, McFarland said Ulster were not hitting their attacking standards but they were much more ruthless here. And when asked about the quick-thinking that fashioned three tries, McFarland revealed the key role captain Iain Henderson had played in concocting the gameplan.

"We were chatting in the week about those tap penalty moves close to the line and we've got a lot of guys who think a lot about stuff like that," explained McFarland.

"It was Hendy [captain Iain Henderson] who came up and said 'why don't we do a maul off a tap penalty, we've got a really good maul, why don't we do that?' So we thought we'd go for that.

"On either Tuesday or Thursday, we apportioned a section of time at the end of training to what we would call 'Labs', or 'Laboratories', where we would test it.

"You take the idea into the 'Laboratory', you all stand around, all the forwards, one of the scrum-halves had to suffer listening to it and we talked through detail.

"I'm really into stuff like that. I love the detail around that and we talk about what-ifs, what the players might do and check with the referees as to whether we're allowed to do that kind of stuff.

"We go away after we've done it and decide if we'll put it into practice. I was wondering if we do both of them or just one of them and to be fair, Hendy said 'nah, let's go for both of them' and they both worked, so fair play."

While clearly pleased by the manner in which his side executed their plan, McFarland warned that Ulster are far from being the finished article.

And with a crucial four-match stretch comprised of United Rugby Championship interpros against Connacht and Leinster, and European dates with Toulouse and Harlequins, to come over the next month, he called for an immediate refocus.

"We only have six days before Connacht come to town," he said.

"They physically caused us problems the last time we were here [when Connacht won last season's URC quarter-final in Belfast] and the way they approached the breakdown in that last game caused us trouble.

"We got on the wrong side of the referee in that game and it's going to be a big challenge, a very different challenge to Racing so it will be interesting but we'll have to refocus for that."