London - Kei Nishikori has started his maiden campaign at the ATP Finals with a 6-4, 6-4 win over home favorite Andy Murray on Sunday.
The fourth-seeded Japanese — the first Asian player to qualify for the year-end championship — was in complete control and secured important points in a tough Group B that also includes Roger Federer and Milos Raonic.
After the round-robin stage, the top two finishers in each group advance to the semi-finals of the indoor tournament at the O2.
Murray only sealed his spot at the season finale last week in Paris following an impressive run that saw him win 20 of his previous 23 matches.
But he appeared tired and never looked capable of turning the match around despite support from the crowd.