Northampton director of rugby Jim Mallinder admitted his players need to be better when they reach the Aviva Premiership play-offs after watching his side "switch off" and nearly throw away victory in their 36-21 win over London Irish.
With two tries from Jamie Elliott and one each from Kahn Fotuali'i and Salesi Ma'afu, Northampton were cruising at 29-0, but three quick second half tries from Andrew Fenby, Shane Geraghty and Jebb Sinclair saw London Irish give the home side a real scare.
Marland Yarde's 60-metre score would have made it 29-28 in the final 10 minutes, but the TMO ruled Tom Homer's pass was forward.
The five points keeps Northampton seven points clear of third-placed Bath and on course for a home semi-final, but a relieved Mallinder said: "We need to be better than that when we come up against the big sides.
"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 Yarland 'try'. We were very grateful to see it called forward."
Mallinder confirmed replacement hooker Matt Williams, who was carried off on a stretcher, had broken his leg, which therefore leaves him with just one fit hooker in Ross McMillan. Mike Haywood and Dylan Hartley are both injured, though Mallinder said the England hooker might be back for the clash at Bath in two weeks when he hopes to have Alex Corbisiero back as well after a lengthy lay-off.
London Irish boss Brian Smith had no complaints about the TMO ruling out Yarde's try or referee JP Doyle not going upstairs for a questionable grounding in Elliott's first try.
"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."