The Marathas decimated the Mughals. That is fact. Not just decimated, plundered and decimated. The Mughal Emperor became a puppet to the Marathas and was confined to a palace. Peshwar, Lahore, NWFP. Conquered by the Marathas after routing the Mughals.
This is not to say, that the Mughals did not contribute anything. But our neighbours false beliefs that the Mughal Empire was defeated by the British is nothing, but utter rubbish. The Marathas for all practical purposes enslaved the Mughal Emperor. Their downfall was their inability to integrate disparate people under one banner.
And to the nutjobs who seem to be spouting venom against the Marathas, because they were Hindu, do not understand Maratha history one bit. The Marathas were Marathas first. Religion second. The Maratha generals who laid down their lives in the Third Battle of Panipat were Muslim. Again, Maratha first. Muslim second. Unfortunately, this is beyond the comprehension capabilities of 99% of this forum.