Lewandowski who committed his future to the Bavarians recently had a superb season last term and has hit the ground running in the new season with 9 goals after five games in the Bundesliga.
Being impressed with the 31-year-old's present form, Toni believes the Polish striker is capable of helping Bayern win more trophies.
“He's is one of the best. I like him so much because he lives in the box and scores a lot of goals," Toni told Omnisport.
"Let's say this: it's really hard to criticise Lewandowski. He is a great player. Sometimes, it happens that he does not score.
"Team success basically comes through strikers' goals. Here we have a strong striker like Lewandowski and I am pretty sure he can lead Bayern to success."
“The Bundesliga has to be a challenging league," said Toni, who won the domestic double with Bayern in 2008.
Despite backing Lewandowski to win more glories with Bayern Munich, Toni wants the Bundesliga to be more competitive but not dominated by the Bavarians as it has been seen in the Serie A with Juventus.
"In Italy, Juventus won the Scudetto last year with lots of games to go, and this often happens in Germany with Bayern.
"I hope for all the Bundesliga and the whole football movement for a very interesting league where three or more teams, maybe an underdog as well, are able to take results against the big teams."
With Bayern securing the services of Philippe Coutinho and Ivan Perisic as possible replacements for departed veterans Frank Ribery and Arjen Robben, Lewandowski is expected to partner well with the creative midfielders for the side to re-gain their lost European status.