BBC Sport - World Championship 2013: Mark Allen trails Mark King 5-4 Northern Ireland's Mark Allen trails England's Mark King 5-4 after the first session of their first round match at the World Championship in Sheffield. The Antrim player lost the first two frames of the best-of-19 match but recovered to lead 3-2 and then 4-3, before losing the final two frames. The world number six must improve his form if he is to overcome King, ranked 30, when they resume later on Monday. Allen, a World semi-finalist in 2009, lost in the first round last year. The winner King-Allen match will face China's Ding Junhui or Scot Alan McManus at the last-16 stage. Allen, who retained his World Open title in March, made an unconvincing start against King, who is making his 14th appearance at the Crucible Theatre. After going 2-0 down, the 27-year-old won the third frame comfortably with the help of a break of 83, the highest of the first session. Allen levelled after a run of 66 and the pair then won two frames apiece, King levelling at 4-4 with a break of 74 before winning the ninth to take a one-frame advantage into their second session.