The Shrimpers remain six points clear at the top of League One despite being held to a draw by Bournemouth.
Fellow promotion rivals Brentford remain second after drawing with Colchester at Layer Road.
But with home games against Blackpool and Gillingham to come, Blues will be hoping to stretch their advantage.
Freddy Eastwood put Southend ahead after 20 minutes as he made the most of a Kevin Maher that caused confusion in the Bournemouth rearguard.
But the Cherries earned a point in the 82nd minute when Stephen Cooke's free-kick found James Hayter and the striker scored at the far post.
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