organised Hornets defence, a penalty from Ryan Taylor and two goals from Andreas Johansson eventually giving them a 3-0 victory.
But Jewell was looking on the bright side, pleased his much-changed team had made it through to the fourth round.
Nine of the players who started Saturday's win at Aston Villa didn't start last night, with only Alan Mahon and Jimmy Bullard pressed into service at the kick-off.
It meant legs were rested for the weekend visit of Fulham to the JJB Stadium, with the Premiership clearly featuring higher on Jewell's priority list than the Carling Cup.
Jewell said: "We should really have had the game won in the first half because we created some great chances.
"We were never at our best but it was nice to step up a gear in extra-time and go on to win it 3-0.
"I don't think the scoreline flattered us as our general play was good, it was just the three goals came together late on.
"The game gave me a chance to give some of the other lads what I hoped would be 90 minutes but turned out to be 120 minutes.
"Everyone came through unscathed and there were plenty of positives to take – Andreas scored his first two goals for us, Ryan Taylor got his first, while we kept another clean sheet.
"It would have bothered me had we gone out of the competition, although I would rather win on Saturday.
"Winning becomes a habit, whatever competition you're playing in, and we're on a good run at the moment."
Jewell accepted a striker shortage meant Latics made hard work of their victory.
Johansson and Gary Teale were paired up front, with Taylor also pressed into an attacking role during the game.
Jewell said: "We're obviously struggling for strikers at the moment, we're a bit short up front.
"Jason Roberts and David Connolly have injuries, so I didn't risk Henri Camara in case we're struggling for Fulham.
"At the moment, Jason is a major doubt for Saturday, although hopefully he can make more progress as the week goes on.
"We missed some gilt-edged chances and could have been made to pay for them.
"But we didn't have a striker on the pitch and I suppose to play as well as we did in patches was a credit to the players.
"The pitch was also very heavy which didn't make things easy – I didn't realise how heavy it was until I went on it before extra-time."
Jewell has already turned his attention to Fulham as Latics go in search of a
seventh Premiership win.
"That will be a tough game, make no mistake about that," he said.
"They beat Liverpool last week and even though they had been losing games before then, their performances were definitely better than their results suggested.
"Fulham are a good side, have pace on the counter attack, and if anyone thinks it is going to be easy, please think again.
"The supporters have a big part to play because it's an early kick-off and probably won't be the biggest gate of the season.
"They have to really get behind us and make it a good atmosphere."