Mark Selby crashed out at the weekend ending his hopes of three-in-a-row

There were only seven World Championship first round matches completed ahead of Monday's evening session at the Crucible but already, two former world champions and and the defending champion are out.

Mark Selby, who completed back-to-back titles last year to add to his win in 2014, suffered a 10-4 defeat to former semi-finalist Joe Perry who had to go through the qualifiers this year.

Perry will face Mark Allen (pictured) in round two after the Northern Irish potter completed a 10-5 victory over Englishman Liam Highfield this morning.

2006 champion Graeme Dott relinquished a four-frame lead to Ali Carter who won their match 10-8, setting up an all-Essex clash with five-time champion Ronnie O'Sullivan.

O'Sullivan emerged the winner out of a tough battle with Stephen Maguire.

This evening 2005 winner Shaun Murphy went from 8-5 up against world number 51 Jamie Jones to 9 frames-all before losing the first final frame decider of the tournament.

Welshman Jones has a tough match-up against Kyren Wilson in the next round.