"Undisputed leader" means someone who is recognized by everyone as the best or most influential person in a particular field or organization. Full definition
As the industry evolves, it will play a role well beyond real estate products and services, individual companies will vie to become undisputed leaders by size and breadth, and ecosystems will develop that have a tight grip on customer loyalty. (retech.net)
That is, until Samsung realized the task might be more difficult than it anticipated, which I should remind you is a sentiment coming from the current undisputed leader in mobile display technology. (gizmodo.com)
The former undisputed leader of the phone business was overthrown in the iPhone and Android revolution. (bgr.com)