Celtic, Betis rival in the Europa League, have lost their third match in the Scottish Premier when they fell to Livingston's fiefdom 1-0, while Rangers, leaders, gave up a draw against Motherwell (1-1).
The Australian Ange Postecoglou's side, who lost on Thursday at Benito Villamarín 4-3, suffered a new setback, this time with a lone target from Andrew Shinnie, which leaves him sixth, four points behind Rangers.
The defending champion, who was early ahead through Zambian Fashion Sakala, was unable to maintain his lead and had his three-game winning streak snapped, leaving him one point ahead of Hibernian and Hearts.