Northampton Director of Rugby Jim Mallinder was far from impressed by his side's showing, despite their 27-16 victory over Sale in Salford on Friday.
Saints, who now move into second having played a game more than Saracens and Gloucester, dominated the first half and scored three tries.
However, they could not cross for the bonus in the second period, which frustrated boss Mallinder.
"I was slightly disappointed with the second half performance," he said following the away success.
"I think in the first half we were very good and dominated the game.
"Our scrum was on top, as well as our driving maul. We defended well and therefore took our opportunities at the right time.
"We talked about doing exactly the same thing in the second half and we didn't do that.
"I'm disappointed with the second half but we got the win and that's important, particularly away from home."
Sharks boss John Mitchell highlighted the pack as where the game was won and lost.
"Northampton's forward pack was outstanding in the first half," he said.
"We never built any pressure or any starting position. In the second half, we showed better character and built some pressure.
"The forwards had a torrid time tonight. We're still very immature as a side and we get frustrated easily, so we've got to learn to become more patient.
"We've got a lot of work to do in the forward area."