Graham Potter admitted Chelsea's 3-0 victory against AC Milan was "really important" as they climbed back into contention for a place in the Champions League last 16 on Wednesday.
Potter's side won for the first time in three Group E games as Wesley Fofana's first Chelsea goal was followed by second-half strikes from Pierre-Emerick Aubameyang and Reece James at Stamford Bridge.
Chelsea had kicked off their Champions League campaign with an embarrassing defeat at Dinamo Zagreb the day before Thomas Tuchel was sacked, while Potter's first match ended in a draw with Salzburg.
But second-placed Chelsea are now level with third-placed Milan on four points ahead of a crucial trip to the San Siro to face the Italian champions again on October 11.
With three games left for each team, group leaders Salzburg are one point above Chelsea after beating Dinamo Zagreb 1-0 on Wednesday.
"It was a good night. We needed to play well. The attitude and application of the players was fantastic. Their personality was good," Potter said.
"It's a really important win but there's still a long way to go in the competition."
Progress in the Champions League is essential to Potter's bid to stamp his authority on a squad expensively assembled by Chelsea's new owners with immediate success in mind.
While Chelsea still have work to do to reach the knockout stage, Potter will be encouraged by the most dynamic performance of his three games since replacing Tuchel.
"The boys have been really open, responsible and fantastic to work with. They realised they weren't at the levels (when he joined). That's great from a coach's perspective," Potter said.
Milan manager Stefano Pioli added: "We weren't dangerous enough, we have to give credit to the opponents, but it's also down to us.
"We knew it would be a tough game but mentally we didn't play as a team."
Potter has kept a low profile so far as he gets acclimatised to the first high-pressure job of his managerial career.
The former Brighton boss had never attended a Champions League game before taking charge at Chelsea, so his first victory in the competition was a memorable milestone for the modest coach.