The resurgent London side put another masterclass show at Stamford Bridge to comfortably beat the Magpies and Tuchel insists top four remains his side’s target.
Chelsea took the lead in the 31st minute when substitute Olivier Giroud - on in place of the injured Tammy Abraham - struck from close range.
The Blues’ advantage was doubled seven minutes later when Timo Werner guided the ball home to end his 14-game goal drought in the Premier League.
Chelsea have won four Premier League games in a row for the first time since November 2019; a run of six under former head coach Frank Lampard.
"I liked the first half where we played with courage and had a lot of touches in the box and lots of shots, and kept them away from our box and did not allow any chances,” Tuchel said after the game.
“During the whole match we lacked precision in the last box and the decision making can be more deadly, precise and decisive to create more from our half chances.
“We gave away two shots in the first two minutes of the second half, we lost duels and the decision making was like we had something to lose.
He added: "Top four is the target and stays the target, there are many teams behind us chasing. We had many points to recover and it stays a big challenge because many games are coming.
“We are going to play teams from the top and bottom, every game is difficult and we will keep fighting."