Watford - Chelsea manager Antonio Conte praised the commitment and focus of his players after their 2-1 victory over Watford at Vicarage Road.
Late goals by Michy Batshuayi, his first for the club, and Diego Costa gave Chelsea three points that seemed unlikely when Etienne Capoue put Watford ahead early in the second half on Saturday.
Chelsea were second-best for the first 70 minutes, but Conte sent on Batshuayi and then Cesc Fabregas and the former scored while the latter had a hand in both goals.
It was the second successive match in which Costa has scored a late winner after his decider against West Ham United last Monday and Conte took heart from his team's battling comeback.
"In these two games we have seen the right spirit, the right commitment," Conte said.
"After a bad season like last year's, it's not easy to start in a good way and win games, and it won't be easy, so we must know that we have to continue.
"It's important to change the situation compared to last season and we are trying to do that with all our strength.
"Yes, the subs had a good impact but I think it's normal when you push for 70 minutes, the opposition pays for the effort it has put in, and when the new players come on, there is an impact."
Conte agreed that his intense fitness regime, which has included double sessions in pre-season, has paid off in Chelsea's ability to perform strongly late in games.
"I believe that work pays and always pays," he said.
"It's important. We are working very hard and we will continue to. And wins like this are very important to improve confidence and trust in the work."
Conte's decision not to start Fabregas in either of this season's Premier League matches has been seen as a sign that the Spain midfielder may not be part of his long-term plans, but Conte praised the former Arsenal and Barcelona star.
"We all know Cesc is a great technical player with a good pass and good assists and I made this substitution because I wanted more quality," Conte said.
"Cesc is working very hard to show me that he deserves to play and I want to see this - all the players showing me that they deserve to start the game and if I see this commitment I'm a very happy manager.
"That all the players think of the team, not himself, is important. And that is happening in Chelsea."
Costa was in the bad books of the opposing fans as usual, this time for a challenge on Capoue that ended the Watford man's afternoon.
But Conte defended the volatile Spain forward, saying: "He scored two goals but I'd have preferred him to score them earlier.
"Diego is working hard like the other players but he can improve a lot. He's an important player for us and he had to stay concentrating in the game."
Watford manager Walter Mazzarri, an old adversary of Conte's from Italy's Serie A, chose to look on the bright side after a frustrating result.
"We played better than at Southampton last week," he said. "Then we played only 20 minutes as I wanted us to play, today we played good football for 70 minutes. We can hold our heads high.
"But in Italy we'd say that we complicated our own lives. Both goals were our errors.
"The value of the Chelsea players you can see for yourself but I would have preferred to concede two goals through their great qualities than our own mistakes."