British number two Heather Watson stunned top seed Elise Mertens to reach the semi-finals of the Hobart International tennis tournament.

Watson, who had to go through qualifying for the tournament, is ranked outside the world's top 100, while Mertens is 17th.

The 27-year-old Brit lost a gruelling first set tie-break 6-7 (5) but fought back to take the second set 6-4 and the third 7-5.

Some clinical hitting from the Brit could prove pivotal as she heads into the first Grand Slam of the season at the Australian Open where she will face Kristýna Plíšková in the first round.

Watson will now take on either Elena Rybakina or Lizette Cabrera in the semi-final in Hobart on Friday.