It is hard to believe, given that they were the first side to win it and were in the final last year, that this is only the fourth time Ulster have made it to the quarter-finals of the Heineken Cup.
They have now made the knockout stages for three years in a row and while they made a bit of history yesterday by winning a competitive match on French soil for the first time, it was a laboured victory.
In fairness, Ulster's march has been impacted by injuries to the likes of Tommy Bowe, Stephen Ferris, Johann Muller and Dan Tuohy, but they looked far from potential Heineken Cup winners yesterday against a Castres side well out of contention, but who still stirred themselves for the fight.
Ulster never looked like getting a try, let alone the four they needed to copperfasten their hopes of a home quarter-final in April.
"We fought for an ugly victory, but it was a victory. It was very flat and there was nothing about us in that first half, but second half we turned it around for a tough win. We are really proud of the guys and the way they went about their week," said Anscombe.
Ulster, given their dreadful record in France, had hoped for a solid start but they were blown away in the opening minutes by a Castres side who quickly laid down a marker that they were not going to roll over easily.
Both sides struggled to master the strong and blustery wind with Ruan Pienaar, playing at outhalf, overcooking his first grubber with the wind pushing it dead.
The task facing Ulster was put into context after eight minutes when Castres went wide down the right and exposed the visitors, with centre Remi Lamerat finishing the move with a try.
South African Rory Kockott was unable to add the points and Ulster, getting an edge in the scrum, started to build the phases and Pienaar settled them with an excellent penalty from 35 metres on the right after 12 minutes.
But it was cancelled at the other end six minutes later when a touch judge spotted an infringement by Paddy Wallace and Kockott made no mistake to make it 8-3.
Ulster's woes continued when No 8 Roger Wilson had to go off with a hamstring injury, with Iain Henderson coming in to the second row and Robbie Diack moving back.
A couple of lineout malfunctions in the Castres '22' cost Ulster dearly after they had upped the ante and taken control of the game.
They seemed poised for a penalty try when they forced a couple of penalties and a reset, but Ulster were then penalised on the next put-in and the chance was lost.
It was left to Pienaar to reduce the deficit four minutes from the break from 25 metres with his side's ninth penalty of the half, but he was unable to edge them in front in the final play of the opening period when his 42-metre effort narrowly missed the target, with the points swirling in the wind.
Castres penned Ulster back for most of the third quarter but eventually Ulster got their lineout sorted and their dominant scrum hauled them back into the game.
Craig Gilroy, Paddy Wallace and Andrew Trimble did their best to crack the home defence but any line breaks were inside their own half.
But the pressure eventually told and Pienaar hit the winner from in front of the posts 16 minutes from time, after Castres were forced offside as Ulster finally starting spraying the ball.
Pienaar had one further chance to extend Ulster's lead but while he judged the accuracy to perfection with a difficult penalty from 35 metres on the right into the wind, it came up a metre short five minutes from time.
Ulster played down the clock after that and a series of picks and drives were enough to seal a famous win, much to the joy of the hundreds of travelling fans.
Scorers – Castres: Lamerat try, Kockott pen. Ulster: Pienaar 3 pens
Castres: P Bernard; M Evans, S Bai (M Andreu 52), R Lamerat (P Bonnefond 63), M Garvey; R Tales, R Kockott (T Lacrampe 55); Y Forestier (S Taumoepeau 46); M Rallier (B Mach 62), A Peikrishvili (M Lazar 53); M Rolland, C Samson; M Babillot (J Bornman 56), P Faasalele, P Wannenburg (I Tekori 69)
Ulster: C Gilroy; A Trimble, D Cave, P Wallace, M Allen; R Pienaar, P Marshall (P Jackson 55); T Court, R Best, J Afoa; L Stevenson, N McComb; R Diack, C Henry, R Wilson (I Henderson 27)
Referee: N Owens (WRU)