Japan's Kei Nishikori suffered a 6-1, 6-4 defeat by Austria's Dominic Thiem at the season-ending ATP Finals on Thursday, ending his hopes of advancing to the semifinals.World No. 9 Nishikori succumbed to Thiem at the O2 Arena in London after producing an upset over six-time champion Roger Federer on Sunday before losing to South Africa's Kevin Anderson on Tuesday."The match was over before I could get a feel for it. Before the tournament, I was playing well but my three matches here were not so good," said Nishikori, who was hoping to reach the ATP Finals semis for the third time in four at…READ FULL ARTICLE