Google's AlphaGo artificial intelligence (AI) program secured a second win against top Go player Lee Se-dol in Seoul Thursday. "I'm quite speechless," said Lee, the South Korean who holds 18 world titles said after losing a match for the second day.

Lee said AlphaGo played a near-perfect game in the second of their five-game match and admitted that he did not feel he was leading at any point during the game.

AlphaGo was developed by Google's DeepMind firm. DeepMind founder and CEO Demis Hassabi praised Lee by saying the amazing game played is a testament to his skills and the team behind AlphaGo is excited and surprised by the result.

The five-game match will continue until March 15, even if a winner is decided after either of them obtains three wins. The winner will receive prize money of US$1 million.