Sunday's 8-0 trouncing of Aston Villa took Chelsea into third with a game n hand on the two Manchester clubs.
And while there is still an 11-point gap to leaders United, the manner of victory suggested Benitez's side could yet have a part to play in the title race.
Next up are back-to-back away games at Norwich and Everton and - on 2 January - a home derby with QPR.
Benitez said: "We will see after two or three more games. You could see the team had confidence in themselves, they believed, and that was there to the end.
"They had good movements, created chances. Now we have to sustain this run and it will be easier for me to say we can compete."
Benitez has recovered from a poor start - two goalless draws and a defeat in his first three games - to oversee an upturn in performances and results, and the Spaniard is grateful to his players for welcoming his arrival with a more open mind than some Chelsea supporters.
He said: "The players were really focused from day one. They knew they had a new manager and they had to perform. The players, from day one, were trying to learn, to improve."
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