Google’s AlphaGo program has beaten Go champion Lee Se-dol by 3-0 in a best-of-five competition.

The match is seen as a landmark moment for artificial intelligence.

Google’s AlphaGo program was playing against Lee Se-dol in Seoul, in South Korea.

Lee Se-dol had been confident he would win before the competition started.

Go is considered to be a much more complex challenge for a computer than chess.

“AlphaGo played consistently from beginning to the end while Lee, as he is only human, showed some mental vulnerability,” one of Lee Se-dol’s former coaches, Kwon Kap-Yong, told the AFP.

Lee Se-dol is considered a champion Go player, having won numerous professional tournaments in a long, successful career.

Go is a game of two players who take turns putting black or white stones on a 19-by-19 grid. Players win by surrounding their opponents pieces with their own.

In the first game of the series, AlphaGo triumphed by a very narrow margin – Lee Se-dol had led for most of the match, but AlphaGo managed to build up a strong lead in its closing stages.

After losing the second match to Deep Mind, Lee Se-dol said he was “speechless” adding that the AlphaGo machine played a “nearly perfect game”.

The two experts who provided commentary for the YouTube stream of for the third game said that it had been a complicated match to follow.

They said that Lee Se-dol had brought his “top game” but that AlphaGo had won “in great style”.

The AlphaGo system was developed by British computer company DeepMind which was bought by Google in 2014.

It has built up its expertise by studying older games and teasing out patterns of play.