Northampton Saints director of rugby Jim Mallinder settled for a 21-18 victory against Benetton Treviso but admitted his team must improve.
Saints scored three tries thgrogh Phil Dowson, Jon Calrke and Courtney Lawes but were forced to cling on in the final ten minutes after a penalty try set up a thrilling climax at Stadio Comunale di Monigo.
Mallinder said: "It's a very difficult place to play. They're a good side, as they showed last week. They scrum well, they maul well, they contest the ball at the breakdown and they've got a big kicking game.
"We made far too many mistakes. We can't blame the preparation. It doesn't help when the kick off keeps getting pushed back but we were poor in the first half. It was always about whether the game would be played or not, but good players prepare for every single game."
Treviso missed four kicks in the first hald allowing Dowson to hand Northampton a 7-3 lead against the run of play, just before half-time.
Mallinder said: "It's always good to score just before half-time and we've done that in a few games recently. It's just a little disappointing that we didn't press on in the second half. We did improve but again it's difficult against a team such as Treviso who play the way they do."
The win put Northampton top of Pool One but their failure to clinch a bonus point could prove crucial come qualification for the quarter-finals of the Heineken Cup.
Mallinder said: "We're well and truly in the competition. We've played four games and won three so we're doing well. We're looking forward to two massive games in Rounds 5 and 6."