Imagination, creativity and critical thinking are long time thought as characteristic that only humans exhibit, it was used to classify humans from animals. However, now-a-days AI also manage to acquire those things, Alphago, who beat the champion of the board-game Go, was a perfect example. 

G0:

Go or Weiqi, is an abstract strategy board game for two players in which the aim is to surround more territory than the opponent. The game was invented in China more than 2,500 years ago and is believed to be the oldest board game continuously played to the present day. 

Kejie vs Alphago

Lets first introduce the main characters of the story

• Ke Jie- Professional go player of 9 dan rank, with a win rate of 74.2% and winning several world championship, he is the top 1 player of Go in the world. 
• Alphago- A computer program that plays the board game: Go. 

What happened?

Google DeepMind offered $1.5 million winner prizes for this match while the losing side took $300,000 for participating in the three games. As the best Go player in the world, Jie quickly accepted the challenge. He has great confidence due to his success and does not believe that a robot will manage to beat him. He played three games against AlphaGo and the result surprised everyone. Alphago won easily won all three games. After the match between AlphaGo and Ke Jie, AlphaGo retired while DeepMind continued AI research in other areas. AlphaGo was subsequently awarded a professional 9-dan title by the Chinese Weiqi Association.

Lee Se-dol is the only human to ever beat the AlphaGo software developed by Google's sister company Deepmind. In 2016, he took part in a five-match showdown against AlphaGo, losing four times but beating the computer once.

Sources:
https://en.wikipedia.org/wiki/Go_(game)
​https://www.bbc.com/news/technology-50573071