An unanswered 382 points from Carter had put him 4-0 up at the mid-session break, and Xiao's luck was summed up by the fifth frame.
Leading 59-52 and down to the final ball, the 29-year-old potted the black but watched the cue ball roll back into the pocket to level the frame.
The black was re-spotted and a battle for position followed, but Carter soon finished it off with a long pot.
And he made no mistake in the next frame to get the evening wrapped up early.
In the afternoon, Judd Trump advanced to the last four with a 5-1 win over Mark Selby, with breaks of 102 and 72 in the final two frames.
Trump will now face Barry Hawkin, who beat Kyren Wilson 5-2 thanks to breaks of 134, 64, 63 and 116.