Mark Selby defeated by Mark Williams in Masters opener

World number one Mark Selby has been knocked out by Mark Williams in the opening match of the Masters at Alexandra Palace.

Williams won the deciding frame to take a 6-5 victory after coming back from 5-3 down to force a decider.

Breaks of 135 and 89 put Williams 2-0 up but Selby bounced back and a break of 70 gave him a 3-2 lead.

Williams levelled the score with an 81 clearance but Selby took the next two frames to take control.

The Welshman needed to win three frames in a row to claim victory, and that is exactly what he did.

Selby posted a break of 32 in the final frame before Williams took the opportunity to claim victory by clearing the table.

Williams will meet Barry Hawkins or Kyren Wilson in the quarter-final.