Ding made breaks of 50, 81 and 61 in a dominant performance. Allen contributed 72 to trail 3-2 before China's number one won the final three frames to secure a meeting in the last eight with top seed Ronnie O'Sullivan or Graeme Dott, who play on Tuesday evening.
2005 world champion Murphy overcame problems with his neck to usurp Kyren Wilson in a 6-3 victory.
Murphy produced breaks of 115 and 133 on his way to opening up a 5-1 lead. Wilson recovered to trail 5-3 before Murphy dominated the ninth frame to seal a quarter-final spot on Friday where he will face the winner of John Higgins or Anthony McGill.
FIRST ROUND DRAW/RESULTS
- Ronnie O’Sullivan (1) v Graeme Dott (16)
- Ding Junhui (8) 6-2 Mark Allen (9)
- Luca Brecel (5) v Neil Robertson (12)
- Judd Trump (4) v Stephen Maguire (13)
- John Higgins (3) v Anthony McGill (14)
- Shaun Murphy (6) 6-3 Kyren Wilson (11)
- Mark Selby (7) v Ryan Day (10)
- Mark Williams (2) v Yan Bingtao (15)