The 28-year-old is the second player from Chinese Tapei to climb to No.1.
A mind-bending marathon bender featured 56 shots and spanned a minute, 22 seconds.
The Swiss returns to the Swiss Indoors Basel after skipping the 2016 event.
Grand Slam king reveals four-point plan to extend career.
Venus Williams is also drawn into the hard-hitting Red Group in Singapore
In a Twitter Q&A, Aussie No. 1 offers views on Mirka Federer, playing doubles with Andy Murray and more.
The Czech says he has suffered back pain since Wimbledon.
