Northampton boss Aidy Boothroyd had mixed feelings after seeing his side secure their first win in seven outings at Sixfields.
First-half goals from Alex Nicholls and substitute Louis Moult earned the injury-hit Cobblers a much-needed 2-0 victory over second-placed Port Vale.
But the victory was overshadowed by Nicholls suffering a broken leg after netting his eighth goal of the season in a tackle that resulted in a red card for Vale skipper John McCombe.
Boothroyd said: "The injury to Alex [Nicholls] has obviously taken the edge off the victory.
"It's a great shame because Alex was certainly looking like being one of our players of the season. I've been in his position myself so I know what he will be going through and I'm sure he can bounce back.
"It was our day in terms of the result but all our thoughts are with Alex. However, we badly needed that victory and now we can have a break from the league."