Their determination to claim their 17th league win of the season and back-to-back victory was frustrated by Stefano Pioli’s men at Stadio Artemio Franchi as they settled for a point.
The draw – their fourth this term – saw them maintain their second spot in the log with 52 points - eight behind leaders Juventus.
Koulibaly helped his side to their 11th clean sheet in 22 league games this term.
“We tried to win it in every way until the last minute,” he tweeted.
Napoli will hope to bounce back to winning ways when they clash with Zurich in Thursday’s Europa League tie.