The former Liverpool coach, 52, is under contract until the end of the current season and replaces Roberto Di Matteo, who was sacked on Wednesday after Chelsea lost 3-0 at Juventus in the Champions League.
Chelsea owner Roman Abramovich, who has fired seven managers during his nine-year tenure, has reportedly made repeated overtures to former Barcelona coach Pep Guardiola, but Benitez said the speculation would not distract him.
“I have a very good relationship with Guardiola. He’s a great manager,” said Benitez, who had been out of work since leaving Inter Milan in December 2010.
“What will happen in the future, you never know. We have a massive game at the weekend (against Manchester City) and five trophies to fight for.
“When you analyse why you want to go to a top side, it’s to win trophies. For one and a half years, two years, I was waiting for the right opportunity.
“I will fight from day one, and we will see what happens.”
Guardiola’s appeal to Abramovich is said to stem from the passing philosophy he helped instil at Barcelona, but Benitez rejected suggestions he will be judged on the quality of football that Chelsea produce.
“I’m not sure what he (Abramovich) is looking for in terms of Barcelona-style passing and playing good football,” said Benitez, who admitted he was yet to meet the club’s owner.
“My thinking is that he’ll be happy with the team winning and playing well. I don’t think there’s only one way to play — whether it’s a passing game, or looking for a long pass.”
Benitez is expected to help Fernando Torres rediscover his best form, having overseen the Spaniard’s development into one of the game’s most feared and prolific strikers during their time together at Liverpool.
Torres, 28, scored 81 goals in 142 appearances at Anfield but has found the net just 19 times since joining Chelsea in January 2011, but Benitez suggested he would not get special attention.
“I talked with him, like the others players,” said Benitez, who held a training session with his new charges on Thursday afternoon.
“He’s one of the important players of this team and I will try to improve him as I improve the others.”
Benitez arrived for his introductory press conference just as the Football Association announced that referee Mark Clattenburg had been cleared over allegations he racially abused Chelsea midfielder John Obi Mikel.
Benitez did not wish to discuss the affair, but when asked about Chelsea’s recent record of attracting unwanted headlines, he said he “didn’t see any problems”.
Benitez also addressed suggestions he had criticised Chelsea during his time at Liverpool, amid reports of supporter discontent at his appointment.
“I don’t remember some of the comments (attributed to him),” he said.
“To be really honest, we (Liverpool) were playing against Chelsea, a top team, in the semi-finals of the Champions League.
“I don’t see this as a lack of respect, more a manager defending his team against a top side.”
Benitez confirmed that he will be assisted by former Dutch international Boudewijn Zenden, who spent three years at Chelsea before working under Benitez at Liverpool.
Chelsea’s loss at Juventus left the defending champions on the brink of elimination from the Champions League, while they trail leaders Manchester City by four points in the Premier League.
Under Benitez, Liverpool missed out on the 2008-09 Premier League title by only four points, and he said he did not feel a need to defend his achievements.
“Have you seen my CV?” he said.
“I have all the trophies you can win at club level.”
Asked about the absence of a Premier League winners’ medal from his trophy cabinet, he retorted: “I won the league twice in Spain (with Valencia). Even Barcelona can’t win the Premier League!”