Tigers were good value for a first-half lead in the clash of former European champions in France, but Toulouse then claimed an opportunist try and kept the scoreboard ticking with a succession of second-half penalties to consign Tigers to a 23-9 defeat.
Cockerill said: “We’re bitterly disappointed because we did so many things right, exactly the way we had talked about all week, but then we made some costly errors at key moments.
“You have to take your opportunities because you’re not going to get many of them on a day like this.
“We came to play one of the best sides in the competition and you have to control the ball. The one time we did not do that we got punished with their try just before half-time.
“You have to manage every minute of the game because if you don’t do that against good sides you will get punished.
“In parts of the game we managed it very well. But there were two or three points which cost us.
“We knew we had to control territory and ball, and I thought we did that really well, but then we turned ball over and they scored when we had been looking to go into half-time with an advantage.
“Even after half-time we were still in the game, but then they came out, they got some pressure, they kicked their penalties and the momentum started to sway against us.
“The effort was fantastic and the mentality was really good but everybody is very disappointed because we had a couple of opportunities we did not take and Toulouse are good enough to be patient and they controlled it better than us.”
Tigers host the Ospreys in Round 2 this Sunday. Tickets are available now.