Proceedings started serenely enough for Murphy, who won the first frame against his lower-ranked opponent at a canter thanks to a break of 84.
However, that was his last positive contribution as he lost the second, third and fifth frames without scoring, registering only seven in the fourth.
Carter makes 147 in defeat, Robertson eases past Maguire to reach last eight
He showed signs of fight in the final frame but a break of 54 could not stop Dott from running out a 5-1 winner.
There were no such problems for Mark Selby, who recorded a routine victory over Noppon Saengkham.
After splitting the first two frames between them, Selby recorded breaks of 55 and 75 to move 3-1 ahead.
The 27-year-old Thai showed signs of life with a century helping to the fifth frame but Selby was undeterred and sealed a 5-2 win.
Selby closes out victory with break of 93
Kyren Wilson edged a 5-4 thriller against Hossein Vafaei.
After losing the first frame, the Iranian ran into a 2-1 lead, winning the second 78-0. The lead became 4-3 after seven but Wilson pulled out the only century break of the match to level it up before closing it out in the decider.
Elsewhere in the second round, Joe Perry defeated Stuart Carrington 5-3, with Mark Allen beating Zhang Anda by the same scoreline.
Jack Lisowski downed Xiao Guodong 5-1 and Ali Carter saw off Alfie Burden 5-2.
'I've won enough titles to be number one' – Rueful Trump loses top spot to Selby after Slessor loss
Walden ends Higgins' bid for record fifth British Open title, full last-16 draw