Claudio Yacob's opener just before the interval on Sunday gave them the chance to take all three points at The Hawthorns, while Nicolas Anelka was guilty of missing an excellent chance for a second for the hosts.
But Jack Wilshere rescued a point just after the hour mark with his first Premier League goal in almost three years.
"We knew we were playing a great team, but we did very well," admitted Congolese international Mulumbu.
"I think we had a great chance to score, Nicolas missed a great chance. We are really happy with point today.
"But we are a good team and now we need to focus on the next game.
"We're strong defensively and were waiting for the counter, but I think we missed a late chance to score and that's why we drew today.
"We started poorly in the first two games but we work as a team and we're really strong now.
"We just need to keep going and I think we're going to do really well this season."