A Google-developed supercomputer has bested a South Korean Go grandmaster again, taking a commanding 2-0 lead in a five-game series that has become a stunning global debut for a new style of "intuitive" artificial intelligence.

After shocking the world by defeating Lee Se-Dol - one of the greatest modern players of the ancient board game - in their opening match yesterday, the AlphaGo computer proved it was no fluke with another victory after a gruelling four-and-a-half-hour encounter.

"I am quite speechless. I admit it was a very clear loss on my part," Mr Lee told reporters after the match, adding he had found "no weakness" in AlphaGo's performance during Thursday's match.

"AlphaGo played a near perfect game today... I will try my best so that I will win at least one game," said an ashen-faced Mr Lee, who had earlier predicted that he would beat the supercomputer by a "landslide".    

The 33-year-old must prevail in all three remaining matches – to be held on Saturday, Sunday and Tuesday - to win the series that has a cash prize of $1 million.

AlphaGo's creators have described Go as the "Mt Everest" of artificial intelligence (AI), citing the complexity of the game, which requires a degree of creativity and intuition to prevail over an opponent.

The most famous AI victory to date came in 1997 when the IBM-developed supercomputer Deep Blue beat Garry Kasparov, the then-world class chess champion, in its second attempt.

But a true mastery of Go, which has more possible move configurations than there are atoms in the universe, had long been considered the exclusive province of humans - until now.