The result ended Liverpool's 11-match league winning run and brought second-placed Chelsea back to within two points of their hosts.
Manchester City are the other team in contention, and Mourinho is adamant it is a race between those two rivals.
He told Sky Sports News: "We're back in nothing. At this moment we are almost third. With Everton's defeat (on Saturday) we were automatically qualified for the Champions League.
"Now with these three points we need one point to finish third. Champions are only one (team) and the champions will be City or Liverpool."
It was a defensive masterclass from Chelsea, with Demba Ba capitalising on a slip from Steven Gerrard to give the visitors the lead just before half-time and Willian making sure in stoppage time.
Mourinho shrugged off criticism of his side's tactics, saying: "It was about winning. We deserved to win, no doubt about it. It's as simple as this.
"With the result at 1-0 for 45 minutes, we were always comfortable. We were never in trouble against a team that is a fantastic team, a team that has beautiful players and scores a lot of goals and smashes every team that comes here.
"Now we can say we won both matches against the champions. If the champion is Liverpool, we won both matches against Liverpool; if the champion is Man City, we won both matches against Man City."
The build-up had been dominated by speculation about Chelsea's team, with Mourinho saying he would rest players ahead of their UEFA Champions League semi-final second leg against Atletico Madrid on Wednesday.
In fact, he made seven changes to his side, including 20-year-old Czech defender Tomas Kalas making his Premier League debut at centre-back.
"We played a good side," Mourinho added.
"Many people would be expecting us to come here and lose three, four or 5-0 like many others did. When people know our focus was on Wednesday, probably many people think it's impossible to get this kind of result.
"Now we have to think about Wednesday, and I would say the game of our lives. To play a Champions League semi-final at Stamford Bridge is something big."