Maxi Lopez scored the only goal on his second debut for the club to leave Sampdoria 13th in Serie A, just two points behind their local rivals and eight clear of the relegation zone.
And Mihajlovic feels it was crucial to return to winning ways after conceding a last-minute penalty in a 1-1 draw with Bologna last time out.
"After the disappointment of the previous game, it was important to win," he said. "Beyond the fact that this was a derby, but because we are now eight points above the relegation zone.
"But now we are thinking towards a delicate game against Cagliari.
"Maxi Lopez? I know him, here he will return to his best - he attacked, defended, helped his team-mates, and scored. Bravo. This is what he does, he helps the team.
"As long as we maintain the balance then the team can continue to play this system - it is good that (Manolo) Gabbiadini and Eder track back to sacrifice themselves for the team.
"The results can be seen. If we continue this way then we can go far."
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