Interim head coach Richie Murphy felt Ulster were “a little disappointing” in their 40-17 win over Montpellier.
The province booked a Challenge Cup last-eight date with Clermont despite trailing 17-7 at half-time in France.
The Top 14 side’s captain Paul Willemse was sent off in the 41st minute and Montpellier were also shown three yellow cards.
“We definitely weren’t at our best and that is a little disappointing,” said Murphy.
Montpellier had been far superior in the first half with their work at the breakdown in particular causing Ulster problems.
The game would hinge, however, on Willemse’s red card for a high hit on Will Addison.
After Addison had scored Ulster’s only try of the first-half, Rob Baloucoune would cross the whitewash only moments after the French international’s dismissal.
Montpellier’s discipline unravelled thereafter, and they were reduced to 12 men for almost ten minutes of the second half after Florian Verhaeghe and Vano Karkadze were sin binned in quick succession, as Ulster ultimately ran in five tries during the second half.
“The performance wasn’t the performance I was looking for,” added Murphy.
“We wanted to back up the decent performance we had against the Stormers (the week before) and take another step in that direction.
“We probably didn’t quite get there but we showed some good character to stick together and get the win.
“Some of that was helped by a red card and a couple of yellows but when that did happen we managed to put enough good phases together to try and see the game out which was pleasing.”
With their previous two games coming in South Africa, and the reward for beating Montpellier another trip to France, Murphy said that travel likely played its part in Ulster’s flat first half.
“We didn’t quite get to the same level intensity-wise that we did in the Stormers game,” he said.
“We talked at half-time about the fact that we hadn’t been that accurate in the first-half, our breakdown was quite poor.
“Our energy levels looked a little bit off in comparison to last week but I suppose some of that may be down to coming back from South Africa.
“We came back into Belfast (on Monday) and back out here (on Saturday). There’s been a big toll on the players over the last couple of weeks.”
Despite the flaws in the performance, Murphy was pleased with the result in what was his first victory since replacing previous head coach Dan McFarland on an interim basis last month.
“It’s knock-out rugby, it’s about winning games,” he said.
“In this competition, we don’t need anything else bar a win at the end of the day. In my time, I’ve only been here two weeks, we hadn’t won yet.
“In that regard, I’m really happy to get my first victory. It’s a quarter-final in Europe.
“It’s not necessarily the competition we want to be in but it’s a great opportunity to try and get into the latter stages.”
