Britain's Heather Watson moved into the semi-finals of the Mexico Open with a hard-fought win over American Christine McHale.

The 27 year-old came through a tough test to take the match 6-3 1-6 6-1 in one hour and 52 minutes.

After breaking McHale twice in the opening set to put one foot in the final four, the New Jersey-based player hit back by winning five games in a row to send the match to a decider.

And when the American held her serve after seven deuces to level things up at 1-1 in the third set, it seemed the momentum was with her to push on and claim the win.

But Watson proved unfazed at spurning three break point opportunities as she went on to win all the remaining games and ease into the semi-finals.

After the match the Brit, who is friends with McHale, said: "I knew I had to be aggressive because she wasn't going to give me any freebies.

"We've been hanging out here every day. We've got both of our mums here, we both went to the party together and have practised with each other.

"It's tough [playing your friend], but we're both used to it."

Watson will now face China's Wang Xiyu for a place in Saturday's final.