Australian Open 2015: Stuart Bingham beaten by Fergal O'Brien
World champion Stuart Bingham suffered a shock 5-4 first-round loss to Fergal O'Brien at the Australian Open.
Bingham, 39, was playing his first ranking match since beating Shaun Murphy 18-15 at the Crucible in May.
The Englishman led 4-2 before Republic of Ireland's O'Brien, 43, ranked 27th in the world, made breaks of 128, 66 and 88 to win the final three frames and the match.
He said: "At 4-2 I found a nice groove and I'm delighted with the finish."
O'Brien will play four-time world champion John Higgins in the second round on Thursday after the Scot beat Michael Georgiou 5-2.
Stephen Maguire and Judd Trump both reached round two after 5-0 wins against Joel Walker and Jack Lisowski respectively.
Since winning his first world title in May, Bingham also suffered an early exit in the non-ranking Snooker World Cup event.
The England pairing of Bingham and world number one Mark Selby failed to make it past the first phase of the competition in China.
World number two Bingham wrote on Twitter: "Well played to Fergal in the last three frames. I didn't do a lot wrong from 4-2 up. Have got to get back on the practice table though. #homebound."