|Betway UK Championship|
|Dates: 23 November to 6 December Venue: Marshall Arena, Milton Keynes|
|Coverage: Watch live on BBC TV, BBC iPlayer, BBC Red Button, BBC Sport website and BBC Sport app from Saturday, 28 November.|
O'Sullivan looked out of sorts for much of the contest and was beaten in a final-frame decider.
Switzerland's Ursenbacher started brightly and opened up a 3-1 advantage, but O'Sullivan hit back for 4-4.
The Englishman went in front for the first time, but Ursenbacher took back-to-back frames for a famous victory.