The Spaniard, who spent six years as Liverpool manager, has been handed a short-term contract until the end of the season at Stamford Bridge following the dismissal of Roberto Di Matteo.
The 52-year-old will be officially unveiled at a press conference at 5.30pm on Thursday, but spoke to Sky Sports News reporters as he arrived at Euston Station this lunchtime.
When asked why he had agreed to return to football with the Blues, Benitez said: "I think it's a top side who want to challenge for trophies. We will think about one game at a time so we'll just try to win the next game."
Many Chelsea fans were unhappy with the abrupt manner of Di Matteo's dismissal, which came in the wake of a damaging 3-0 UEFA Champions League defeat to Juventus in Turin on Tuesday night.
There have been reports of unrest among some supporters with several claiming they will refuse to go to the next game in protest at Roman Abramovich's ruthless dismissal of the Italian.
But Benitez remains confident that victories early on in his reign will quell any fans' revolt, adding: "The fans all want the same thing as the manager - and that's to win games."
Four league games without a win have seen Chelsea slip four points behind leaders Manchester City, who they face live on Sky Sports on Sunday.
Benitez will be reunited with Fernando Torres in west London and will be hoping to bring the best out of the struggling striker, who enjoyed a prolific spell while working with him at Liverpool.
The 52-year-old is expected to name Boudewijn Zenden as his assistant according to the Dutchman's father and agent.
And he must find his feet fast, with London derbies against Fulham and West Ham on the horizon following the top-of-the-table clash with City.
Benitez has been drafted in by Chelsea in their hour of need due to his vast experience of Premier League and European football, and they are convinced that they have the right man for the job.
On announcing his appointment, a statement released by the Blues read: "Chelsea Football Club can confirm Rafael Benitez has been appointed interim first-team manager until the end of the season.
"The owner and the board believe that in Benitez we have a manager with significant experience at the highest level of football, who can come in and immediately help deliver our objectives.
"The 52-year-old Spaniard is due to meet the players at the training ground in Cobham on Thursday.
"The two-time UEFA Manager of the Year comes with outstanding pedigree. He began his managerial career in his homeland, most notably at Valencia where he built a reputation as one of Europe's top coaches by winning the Spanish League twice and the UEFA Cup.
"He then spent six years at Liverpool and led them to their fifth European Cup and an FA Cup."