David Flitcroft felt his team's lack of ruthlessness at crucial times cost them the chance to take important points at Luton Town on Monday.
The Stags lost 2-1 despite leading at the break thanks to Kane Hemmings' 12th goal of the season.
And with his side sitting just outside the play-off zone, Flitcroft, in assessing Monday's display, knows what's needed to get back into it.
He said: "Over the 90 minutes, not many teams will come here and give Luton the problems we have today.
"It's those match-winning moments though where we've not helped ourselves. If you're not pristine in those then you run the risk of undoing all the hard work done and the shift put in.
"Whether it's a shot, the final ball, the end product - we're not killing teams off. Added to that, we probably didn't react quick enough when Conrad spilled the shot that led to their goal whereas their players did, and that can be the difference.
"In the second-half we had chances to open them up and kill them off. We need to give everything to each other - when Lee Angol had a great chance it was their defenders that put everything on the line to get the ball clear and we have to be like that.
"You're in control of what you do and it's what happens in both penalty areas that define you over a season, not how well you may or may not have played or even the effort put in."
Flitcroft remains winless in his six-game spell as Stags boss but says he is now beginning to see signs that a corner is being turned.
He said: "They're showing me signs of being a team that's desperate to win and that's what we have to show in the last six games of the season.
"We need to cut out the errors and make sure those match-winning moments go our way.
"If you put the game against Forest Green to one side, I've seen plenty in games like Notts County and even against the top sides like Accrington and Luton that enthuses me and that spirit is being galvanised. They're starting to play how I want, open teams up and create chances. Now it's about killing them off.
"We've deserved more over Easter and the fans certainly have. They've been fantastic in spending their money on two games in quick succession and travelling down to support us here. They've got behind us and now we have to reward them by getting points on the board."