Craig Elliott watched his Boston United side stretch their unbeaten run to six matches - before telling them he expects more.
The Pilgrims have picked up 16 points from a possible 18 since the start of December.
However, after beating Tamworth 3-1, Elliott said his side can still make important improvements
“There are things we can still do better,” he said.
“We talked about playing well and keeping a clean sheet, and in the second half I felt we played well enough to keep a clean sheet.
“It was an individual error which could have been sorted out and that puts a dampener on it really.
“It’s not just winning matches, it’s the manner in which you win matches. Clean sheets give you confidence.”
Ashley Hemmings scored twice and Reece Thompson was also on target before Blake Reid grabbed the Lambs’ consolation.
Boston have scored 14 times in their past six National League North games, but Elliott was also left frustrated by missed chances yesterday.
“It’s something we talked about and worked on in training,” Elliott added.
“We need to be more clinical in this league.
“You don’t get too many chances sometimes and it’s about putting teams to bed.”