While it was his 20th goal of the season, it was Ellington's first since netting the winner at Crewe almost a month earlier.
Jewell said: "The Duke gets a lot of credit and a lot of attention because he is the record signing here and a goalscorer.
"I thought his goal against QPR was a good goalscorer's goal and we were all delighted to see it go in. Some might say it looked a bit lucky but I thought he reacted very well to put his chest on it."
Ellington's strike was enough to earn Latics victory in London and end a run of four consecutive draws.
With Crewe and Cardiff both winning over the weekend, it was a vital result and kept their 12-point cushion at the top of the table.
It also officially guaranteed Latics at least a play-off spot.
Jewell said: "It was a big win for us from a hard fought and very physical games.
"At this stage of the season, it is all about results, and you don't tend to get many good games because teams are playing for so much.
"I'm just delighted we came away with a clean sheet and a win. It was a guts and determination day, and we showed plenty of both which was very pleasing.
"I thought we started the game brightly and created some decent chances - the Duke hit the post, Lee McCulloch had a header, and then Neil Roberts had a chance after we scored.
"But it was never going to be pretty on a hot day, playing on a bumpy pitch - it was all about the result.
"We knew QPR are a big side, and while in the first half I thought they out-muscled us at times, we matched them challenge for challenge in the second half."
While the celebrations among the players at the final whistle indicated that promotion is getting ever nearer, Jewell still wasn't getting carried away - in public anyway.
"We aren't there yet and there is still a lot of football to be played yet," said the boss.
"I know some people are saying we are up, and reading the programme before the game, it was saying 'congratulations to the champions.'
"We don't take that – remember we've had that terrible blip of one defeat in 33 games and drawn our last four – so we were just pleased to get back on the winning trail."
Jewell reported no major injury worries from the game, although he took pre-match doubt Tony Dinning off at half-time and replaced him with Jason Jarrett.
He said: "That was a tactical switch but I didn't think Tony was quite as fit as he was. He was off the pace a little bit and perhaps that was down to the fact he's had a calf strain."
Article from the Wigan Evening Post.