Cameron Norrie has been eliminated from the ATP 500 event in Acapulco after losing in three sets to world number six Dominic Thiem.
British number three Norrie came through two qualifying matches to reach the main draw of the tournament in Mexico, but was handed a clash with third seed Thiem.
Norrie struck during the closing stages of the second set to take the match into a decider, but Thiem had the better of the third and eventually struck in Norrie's final service game to seal a 6-3 5-7 7-5 win.
In the women's event, British number two Heather Watson faced Beatriz Haddad Maia, but succumbed to a 5-7 6-4 1-6 defeat at the hands of the Brazilian.
Watson competed well during the opening two sets against a player 11 places above her in the world rankings, but Haddad Maia dominated Watson's serve in the decider to progress through to the last 16.