Livingston inflicted a first domestic defeat of the season on reigning champions Celtic with a 2-0 win at the Tony Macaroni Arena on Sunday lunchtime.
The visitors had Ryan Christie sent off for a bad tackle midway through the first half and Scott Robinson and Lyndon Dykes struck in the second period.
In the later game, Rangers thrashed Hamilton Accies 5-0 at Ibrox to take over at the top of the table. Jermain Defoe grabbed a hat-trick and Connor Goldson and Borna Barisic were also on target for Steven Gerrard's men.