Martinez's men remain in the bottom three but have a game in hand on 17th-placed Sunderland.
He told Sky Sports 1: "It's a great point because we were 1-0 down and a late goal like that is a point gained, there's no two ways about it.
"But overall we were very poor and I think that's the worst performance we've had this season.
"We were cagey. If anything the sending-off went against us. We are a team that enjoy having the ball and we can open teams up but we made it a hard task.
"The players know that they haven't done things as well as they should have done but that result is very, very important."