After bowling Australia out early on day three, the Three Lions found themselves on 49-3 before Bell hit 105 not out to leave the hosts with a lead of 202 at stumps on 234-5.
Hussain was full of positives for Bell, who has come under fire in the recent past for not scoring enough runs.
"England have had a really good day," Hussain told Sky Sports News. "They've come in, bowled Australia out when everyone was presuming - and Australia were hoping - they'd get a lead of about 100. They didn't get that and England's bowlers set it up for them today.
"Then Ian Bell delivered yet again. There's that myth that people used to say about Bell only getting runs when others get runs ahead of him - well Bell has got runs in this series when no one else really has.
"We all know he's very strong through the offside and there have been a number of cover drives but he's got the back cut going well, too. He put the big shot down the ground away after being caught in the first innings and produced a very controlled, very disciplined innings and was very pleasing on the eye, as he always is."
The century was Bell's third of the series.