Nottingham Forest forward Simon Cox is aiming for a quicker than expected return to action from the foot injury that has kept him sidelined for the last three matches.
The Republic of Ireland international suffered a detached ligament in November's victory over Wolves and was expected to miss up to two months, but could now return earlier.
He told the club's official website: "I feel good, I'm progressing day by day and hopefully it won't be too much longer.
"I've been away for a week and a bit of warm weather has helped me. I'm not on crutches any more or using the air cast boot - I'm walking around pain-free.
"I'm quite fortunate in so much that I seem to recover from injuries pretty quickly but I know I need to get my ankle right before I really push on.
"It's a case of so far so good but I don't want to rush things and jeopardise the way things have gone."
James McClean put the hosts ahead early on and they wrapped up three crucial points with further efforts from Steven Fletcher and Stephane Sessegnon.
O'Neill said: "I am delighted to have won, naturally, and there's a sense of relief too that we have done that. It was good to win the game."
The win lifted spirits at the Stadium of Light enormously ahead of a difficult run of fixtures including Saturday's trip to Manchester United and a visit to Southampton before champions Manchester City head for Wearside.
He said: "It's the winning of football games. It doesn't matter about performances.
"We had a really excellent second-half performance against Norwich which yielded nothing - although you might say in the first half, we probably didn't deserve it - and we showed a lot of commitment against Chelsea here.
"But you can talk until you are blue in the face, you have to win some football matches, and it's definitely just a great old feeling.
"Of course, we have got tough times ahead at this minute, far from anything being clear.
"It might have lifted us a couple of places in the league, but it's the points on the board that are essential, and we have got a really tough time between now and New Year.
"We will just have to try to see it through if we can, but that was a boost tonight anyway for us."