In a chaotic, unorganised sprint finish on a wide road, Magner launched his bid for the line relatively early with a few hundred metres to go.
It looked like the 26-year-old, who hasn't had a pro win since 2012, would falter especially with hardened sprinter Travis McCabe behind, but his lunge to the line was enough to put a wheel in front of he and Lawless.
"Coming into the last kilometre, I saw Travis coming up the right side, and saw some Rally guys going up the left side," Magner explained in the post stage press conference. "Even further to the left there was a BMC guy going.
"I swung all the way right and got on Travis to the final corner. Murph came up my inside, and we just found each other again through the corner, which is kind of what we said would happen. It was all over the place, that last two kilometres really."
The stage started with the anticipated breakaway struggle, a group of 10 riders only pulling clear towards the end of the first categorised climb. Their advantage built to over five minutes, but after another 50 kilometres of racing, the breakaway blew apart on the second ascent of the Logan climb, the catch made eight kilometres from the finish.