That seemed to play out in the evening's group final against 2010 world champion Robertson who just had too much quality in the end.
Walden won the first frame with a 43 and an 87 only for Robertson to level at 1-1 with a 63.
A 134 saw Robertson move 2-1 clear, but Walden won the next two frames including 45 and 61 in the fifth frame.
It was to be the last frame he won as Robertson levelled at 3-3 with a 59 before battling his way to the next three frames to set up a meeting with his rival Judd Trump in the last four on Saturday night.
Defending champion Ronnie O'Sullivan and Ding Junhui contest the first semi-final on Saturday afternoon.