Google's artificial intelligence program, AlphaGo, beat Chinese Go master Ke Jie for a second time on Thursday, taking an unassailable 2-0 lead in a best of three series meant to test the limits of computers in taking on humans at complex tasks.

The victory over the world's top player - which many thought would take decades to achieve - comes after the AI program from Google's DeepMind unit bested South Korean Go professional Lee Sedol in a similar exhibition match last year.

The victory is a feather in the cap for Google parent Alphabet's ambitions in the artificial intelligence arena, as it looks to woo Beijing to gain re-entry into the country.

AlphaGo faces off against Ke Jie once more on Saturday.

Go is a highly complex board game dating back thousands of years that involves two contestants placing black and white stones on a grid. It is popular in Asian countries and most top-ranked players hail from China, Japan and South Korea.