Heather Watson reaches first quarter-final for 18 months with epic win

Watson will now face Chinese seventh seed Xinyu Wang in the last eight

Heather Watson reached the last eight in Thailand (Adam Davy/PA) (PA Wire)

Heather Watson is through to her first quarter-final in 18 months after a marathon three-set win over Han Na-lae at the Thailand Open.

The British No 6 will climb back into the world’s top 150 following a 6-3 5-7 6-4 victory lasting two hours and 33 minutes.

Watson, 30, led by a set and a double break before her South Korean opponent found her range and hit back to force a decider.

A break ahead in the final set, Watson hurled her racket in frustration after being pinned back to 4-4.

But she regained her composure to break once more and then finished the job with a superb drop shot on her second match point.

Watson will face Chinese seventh seed Xinyu Wang, the world No 81, in the last eight.