The 28-year-old England forward this week agreed a lucrative new deal to keep him at Old Trafford until 2019 and duly followed up Robin van Persie's penalty to rubber-stamp United's first league win in four attempts.
The deal had taken some time to negotiate but Rooney stressed after Saturday's match at Selhurst Park that his commitment had never wavered, and he was now just looking forward to playing his part in the club's future.
"I've been trying to do well for the team and trying to help us win," he told Sky Sports 1.
"Whether I'm signing a new deal or not I always give 110 per cent on the pitch and that's what I've done today.
"It's been more or less agreed for a month now and it was just the fine details that needed sorting. I wanted to get it done as quickly as possible and thankfully it's behind me and I can concentrate on my football.
"Obviously I've been letting my football do the talking but I'm happy and settled."
Rooney admitted it was a vital victory at Palace, as United moved up to sixth place in the Premier League and closed the gap on Tottenham in fifth to five points.
They still trail fourth-placed Liverpool by eight points, having now played a game more, but Rooney was encouraged by the performance against Palace.
"Today was a big result for us," he said.
"It was a good victory. I thought we played well and it was a good win.
"We moved the ball well, maybe could have created more chances but overall we were in control of the game and once we got one goal we knew we'd get another and see the game out.
"It's tough getting that first goal but thankfully Robin put the penalty away and I think it was a great three points."