world no 1 mark selby overcame a neck injury to beat fellow englishman elliot slessor at the china open .
john higgins and ding junhui have also made it into the tournament 's last 16 .
shaun murphy was made to work hard for his place in the third round , coming back from 3-2 down to beat anthony mcgill .
the last 16 will take place across two sessions on thursday .