With Northampton likely to miss out on the Heineken Cup quarter-finals, director of rugby Jim Mallinder lamented being drawn in a tough pool.
Saints put in a dogged performance to beat Castres 13-3 at Franklin's Gardens on Friday but Leinster's thrashing of Ospreys meant that the English club had to settle for second place in Pool One.
Only an unlikely set of results this weekend would see Northampton finish as one of the two best runners-up and avoid failing to reach the knockout stages for a third consecutive year.
Castres had nothing to play for on Friday yet the strength of their display, especially on defence, highlighted what a tough group it was.
While content with his team's performance, Mallinder feels it was the defeat in France in Round One that ultimately cost his side top spot in the pool.
"They are the French champions and they proved it," said Mallinder after the hard-fought tussle.
"Their defence was very good, their line speed cut down our options, stopped us getting on the front foot and getting any momentum.
"You asked what we have learned from the Heineken Cup this year, and first of all you could really do with an Italian side in your pool rather than three quality sides.
"We will also look at the game down at Castres and think that was a big opportunity we missed. We gave them an interception try early on. We came back into the game and very nearly won the game. But when you are up against good sides like that you have really got to take your opportunities."
Northampton skipper Dylan Hartley praised his side's character for squeezing out a positive result.
"Before the game I said 'let's not worry about the maths, let's just win tonight and see where we are at. Whatever competition we will be in we will give it a good crack'," said Hartley.
"We showed plenty of character to play to 80 minutes against the French champions and take that opportunity right at the end. As frustrating as it was to watch, playing it was equally frustrating.
"With nothing to play for you might have expected them to fold, but they didn't. We probably should have got the scoreboard ticking over early on, but I decided to go for the pushover try and it didn't come off. If we had gone 3-0, then 6-0, 9-0, 12-0 they might have shut up shop.
"But if you have a feel for it on the field you have to go for it, the scrum was dominant so you have to go for it."
Man of the Match Tom Wood said that while they didn't get the tries they wanted, Saints can be pleased with the win.
"We always want to push for four tries and go for five points," he told SaintsTV.
"We knew in the back of our minds that that was what it was going to take if we were going to put pressure on Leinster.
"But we were under no illusions. We were up against the Top 14 champions who brought a big heavy pack. There was speculation during the week about whether they'd bring a second team given that they're out of the competition, and away from home French teams can sometimes lose focus.
"But they came here to play and picked a pretty much full strength side. They gave us a real game. They were really stubborn in defence, came looking for the big hits and we had to front up.
"We took scrums early on with the view that we would grind them down and hope that some gaps would open up later on, but fair play to them, they're not Top 14 champions without good reason.
"They stuck with us all the way and it was just pleasing to get the win, never mind the four tries."