The defender's 85th-minute finish salvaged a point just as it looked like the hosts were going to take all three through midfielder Luke Howell's 61st-minute strike.
John Still's misfiring side are without a win in six, while Accrington's second successive draw continued their solid start to the new campaign.
Romy Boco shot wide after just 33 seconds as the visitors started the brighter and Padraig Amond and Lee Molyneux went close.
But having endured some early pressure it was Still's men who went ahead courtesy of Howell's neat close-range finish just after the hour mark. The midfielder latched on to Gavin Hoyte's inch-perfect pass to fire home.
However, with five minutes remaining Murphy collected a pass from Molyneux to level matters.
Substitute Danny Green headed wide in injury-time with what would have been a winning goal.