Northampton Saints boss Jim Mallinder cited his side's lack of momentum at the breakdown for their loss to Castres away in France.
The Top 14 champions outmuscled their English opponents around the contact area as they were well-marshalled by South African scrum-half Rory Kockott.
Mallinder was happy with Northampton's set-piece work and defence, along with having gathered a crucial losing bonus point, but admitted that Saints' early tactics backfired.
"It was always going to be a bit of a scrap out here. It's the way they play, they're a good side with a big chunky pack, bossed around well by Rory Kockott and that's what happened today," said Mallinder.
"We came with the intention to play some rugby, which backfired against us a little bit in the first minutes with that interception.
"What Castres did very well is slow us down, we struggled to get any real quick ball in the contact, we struggled to get on the front foot. When you combine that with hard decisions from the referee, it gets frustrating.
"Our set piece was solid today, our scrum in particular did well against a massive pack. Our defense is looking good, and generally our game is in good shape.
"We came back into the game and had our chances. If we had taken those we could be the ones smiling right now. Instead we're frustrated that we couldn't get a win, but it is a point."
Meanwhile Castres coach David Darricarrere hoped that the 19-13 victory would breathe new life into his team's stuttering season, with the defending French champions currently 11th in the league.
"The Heineken Cup was a perfect opportunity to get some confidence back and we're very satisfied with the result," said Darricarrere.
"We got the win through spirit and determination we put into the game against a high quality side.
"The boys put their guts into that game. We would have loved for it to go down even better with more possession but even that says a lot about how much the boys worked to get the win."