Sam Allardyce says he "dreads to think" where Sunderland would be without the goals of Jermain Defoe.
The Black Cats trailed Chelsea 2-1 in the 67th minute on Saturday, when Fabio Borini's powerful drive squirmed beyond Thibaut Courtois.
Defoe then struck his 15th Premier League goal of the season to complete a remarkable comeback, sending Allardyce's team out of the relegation zone with a 3-2 victory.
The former England man has scored 18 goals in all competitions this season, 13 more than any other Sunderland player
"You give Jermain Defoe a chance and generally he at least hits the target," said Allardyce.
"We've crawled out of the bottom three by the number of goals that he's scored. Without him I dread to think where we'd be as a team."
Allardyce suggested his tactical switch to move Borini closer to Defoe paid dividends.
"That little change of tactics, by pushing Fabio Borini in the middle behind Jermain Defoe, has obviously paid off," he added.
"It's a wonderful comeback and wonderful for us. We're the favourites [to stay up] now, Newcastle have been favourites all this week."
A win for Sunderland at home to Everton on Wednesday would secure their top-flight status and relegate Newcastle United and Norwich City.
"Our destiny is in our hands and a win against Everton will secure our Premier League future. It will be difficult but we have an opportunity to achieve it, let's hope we can," said Allardyce.
"Since the turn of the year we've been so near yet so far from so many victories, but today, for a change, we've come from being behind twice and come back to win the game and it shows the character of the players."
The manager also singled out goalkeeper Vito Mannone for praise after the Italian made a string of impressive stops to deny Diego Costa twice and Willian in the second half.
"Our goalkeeper made two unbelievably good saves which has given us the platform to score two quick goals to get in front. Every man has done his job today and done it very well," he added.
