Northampton boss Jim Mallinder has admitted that his team will have to play better against tougher opposition in the weeks to come.
Saints were given a scare by London Irish after they fought back from 29-0 down to trail only 29-21.
Mallinder conceded his team switched off in the second half after securing the bonus point try.
"We need to be better than that when we come up against the big sides," said Mallinder.
"At half-time we spoke about keeping that intensity to our game and we did for the first 10 minutes. We got the fourth try and then we seemed to switch off, getting turned over twice in the final third and seeing them go the distance - and then it gets a bit squeaky.
"It is really disappointing as it was a game which could have been a convincing win, but ends up being in the balance.
"I was delighted to see the referee refer the Marland 'try'. We were very grateful to see it called forward."
Irish boss Brian Smith had no complaints over the controversial awarding of Jamie Elliott's first try, with the winger appearing not to have grounded the ball, or the disallowed try for Marland Yarde that would have secured a try bonus point.
"I thought the pass was marginal, so I don't have too many complaints," said Smith.
"Some days you get the tick and some days you get the cross. We were playing away so it was understandable we got the cross today.
"I understand there might have been some problems with the grounding in the first try, that is a matter for the referee and TMO. If the TV are showing it is wrong then that is a learning point for him and you just role with the punches. We just hope at the end of the season we get as many good calls as bad calls.
"We rallied really well in the second half, but we can't be happy with the first half. We made lots of skill errors and they feasted on them."