Alejandro Garnacho and Rasmus Hojlund scored as United came back after conceding to climb up to 11th in the Premier League standings.
The victory at Old Trafford came a day after Ten Hag said rumblings about his job were media "fairytales and lies".
Asked if it could be a turning point in the season, Ten Hag said: "No, it is just a win. The pressure is always there. We have to win every game.
"Every game we win is important. This team, you see the togetherness, a fighting spirit. Today we had some determination to score goals, and that's what we need. Today we scored two brilliant goals and we are very pleased with it."
United kicked off the game level with Crystal Palace for the league's fewest goals scored this season (five) which Ten Hag blamed on his team's horrible start to the season.
"This team has the capacity to score very good goals," the Dutchman said. "Today the two goals we scored were high quality and when you score and win you add confidence.
"At the start of the season we had some good performances but didn't score enough, then everyone is negative.
"This result can help us, but it is only one win and we must build on it."
Ten Hag had high praise for Marcus Rashford, who has been the target of criticism from fans but had a superb game including a pinpoint cross that found Garnacho at the back post for United's first goal.
"Really enjoyed how he played, you see what he's capable of, a lot," Ten Hag said. "We want this every game, really intense and then a brilliant cross. Starts with fighting spirit. When we all bring this we have a team that can play for trophies."
