Baker Mayfield's first game as a Cleveland Brown wasn't just impressive ... it was ONE OF THE GREATEST STARTS EVER -- so says NFL Network analyst Brian Baldinger.
Baker took over for starter Tyrod Taylor in the 2nd quarter of Cleveland's game against the NY Giants Thursday night ... and lit it up -- chucking two TD passes.
Baldinger -- who had a long NFL career as a lineman in the '80s and '90s -- was floored ... calling it afterward, "one of the greatest rookie quarterback debuts I've ever seen.