Anthony Hamilton's title defence ends in first round as Masters champion Mark Allen loses

Top seed Hamilton made a break of 66 in the third frame, but it was Robertson - the world number 37 from Bexhill-on-Sea - who was largely the dominant figure with knocks of 73 and 50 helping him to establish a 4-1 advantage at the German capital's Temopdrom.

Hamilton was first among the balls in the sixth frame, but could not capitalise as a late safety error by the Nottingham professional allowed Robertson to complete his progress.

Robertson will face Gary Wilson for a quarter-final spot after his 5-2 win over Martin Gould.

Masters champion Mark Allen is also out after suffering a surprise 5-4 defeat to Matthew Selt.

Selt led 3-1 and 4-2 courtesy of breaks of 101, 68, 51 and 61.

But Allen added to his 97 in the second frame by compiling 72 and 100 to force the decider. It was Selt who kept his composure to dominate the frame in securing a meeting with Mark Williams in the last 16.

Northern Ireland Open winner Williams enjoyed a 5-3 win over Fergal O'Brien.

World number five Ding Junhui completed a 5-2 victory over Michael Georgiou with the highlight of his progress being an immaculate 131 in the fourth frame.

The former World Championship finalist also produced runs of 55 and 56 to reach the last 16 where he will face Ricky Walden after his 5-3 win over Jack Lisowski.

There was also a 5-4 win for former Masters runner-up Joe Perry over Yu De Lu with 'The Gentleman' contributing a highest break of the match of only 59 in the deciding frame.

Perry will meet Judd Trump after the former UK champion completed a quickfire 5-3 victory over Ben Woollaston in the last 16.

Trump produced breaks of 109, 68, 94, 103 and 78 with Woollaston producing 114, 70 and 104 in a high-quality meeting.