Chances were largely few and far between in a poor quality npower Championship game that was disrupted by a sticky pitch and a goalless first half passed without incident.
The scrappy play continued in to the second half and the game looked as if it was heading for a draw until one moment of real quality in the 81st minute provided the home side with their winning goal.
Michail Antonio worked hard to keep the ball on the right-hand side before providing a superb cross that was headed home off the underside of the bar by Leroy Lita. It was enough to secure the three points and extend Wednesday's unbeaten run to a seventh game.
Wednesday manager Jones said: "It was a hard-earned win from a dogged performance. I thought we were solid, we protected Chris Kirkland really well and I think we deserved the win in the end.
"I was really pleased with the goal, it was a fantastic ball in from Antonio and you know what you get from Leroy, it's what he's all about.
"He was hardly in the game for long spells but when he gets the chance he usually puts the ball in."
Palace manager Ian Holloway was disappointed with his side's inability to battle.
Holloway said: "We struggled to get our game going and they seemed to have a bit more belief about them than us. The second half was better and I thought we looked the team more likely to grab a goal but it just wasn't to be.
"The defending for the goal was poor, we let them get a cross in and Leroy did what Leroy Lita does and put the ball in the back of the net. I don't think we deserved to lose, but did I think we did enough to win it? Probably not, I felt a draw would have been a fair result."
- Sports & Recreation
- Leroy Lita