Celtic outgunned Astana on every level, as Scott Sinclair's brace led them to victory and all but guarantees UCL group stage football.
Sergio Escudero opened the scoring and a cheeky finish late on from Wissam Ben Yedder put Sevilla in perfect position heading into leg two.
Olympiakos spared themselves a surprising loss, scoring two unanswered goals, with Alaixys Romao's scoring the late winner.
Goals from Dries Mertens and Jorginho were enough to earn Napoli a 2-0 win against Nice in their Champions League qualifying play-off first leg.
Trent Alexander-Arnold's superb free kick set Liverpool on course for a 2-1 win at Hoffenheim in the first leg of their Champions League playoff.