Mark McCall admitted Saracens had to dig deep in their 29-20 Champions Cup quarter-final victory over Northampton at Allianz Park.
England wing Chris Ashton crossed in the 69th minute to finally put the tournament favourites in control before Chris Wyles produced a late try to sweep the game beyond Saints’ reach.
“This was a complex match for us. In the first half we didn’t play anywhere near to the level that we can,” director of rugby McCall said.
“We just needed to find a way to turn the energy of the game around. Give Northampton a lot of credit because they put us under all sorts of pressure at the breakdown.
“Good teams find a way of getting the job done. We were nowhere near our best and the last few weeks in the Premiership were almost too easy for us in a way.
“These games are different, there’s a lot at stake. This was the first game of the season where it’s on the line and if you lose you’re out of the competition.
“Maybe we played not to lose a bit and we were lucky to be only four points down at half-time.
“We know we’ll have to improve a lot of things against Wasps in the semi-finals,” added the Northern Ireland born McCall.