Masters: Defending champion Shaun Murphy out after losing to Mark Allen

Defending champion Shaun Murphy has been knocked out of the Masters after losing 6-4 to Mark Allen in the opening round at Alexandra Palace.

Murphy defeated Australian Neil Robertson in last year's final and he refused to give up his crown without a fight.

The 33-year-old battled back from 5-2 down to 5-4 before both players committed mistakes in an error-strewn 10th frame that eventually went to Northern Irishman Allen.

After the first two frames were shared, Allen moved ahead with a break of 137 and then made it 4-2 when Murphy forfeited the frame following three misses as he attempted to connect with a loose red.

Another century run of 104 put Allen one frame away and, although Murphy managed a break of 100 in the ninth frame, he could not complete the comeback.

Allen will now face either Barry Hawkins or Joe Perry in the quarter-finals.

Murphy later defended his decision to try and play the same shot for a third time in the sixth frame, despite subsequently having to forfeit the frame as he was not snookered when attempting the shot.

"It's the rule. You don't see it very often," he told worldsnooker.com.

"Normally you would look for an alternative on the third go. I couldn't see a Plan B.

"All other options left him a guaranteed chance so I had to man up, take a deep breath and play the right shot. Unfortunately I got it completely wrong.

"Did I lose the match because of it? No, I don't think so. There were plenty of other frames.

"I thought it was a really good match played in very good spirit. That match could have been the final of any tournament.

"Unfortunately for me it was the first round and I'm on my way home."

Allen was pleased to advance in the competition, despite having to beat his friend Murphy to do so.

"Shaun is the defending champion here, under a lot of pressure, and it was a big match for me playing him on the big stage," he said.

"I'm very happy with the way I played, I scored heavily, took my chances well and got over the line in the end."

In Sunday's other match, Stuart Bingham missed out on a 147 break on his way to a 6-4 victory against Ding Junhui.

Bingham battled back after losing the first frame to level and was on a break of 120 in frame three when a missed yellow cost him his chance at a maximum clearance.

He still took the frame 124-0 and claimed the fourth as a break of 60 secured a 70-21 success to lead 3-1.

Ding proceeded to take the next two frames to level at 3-3 before Bingham won the seventh frame 80-5.

A run of 71 brought Ding level again but Bingham won the next to edge 5-4 ahead.

The reigning world champion then edged a scrappy 10th frame secure his place in the quarter-finals for the first time in his career.