British number two Heather Watson was knocked out of the Abierto Mexicano Telcel after a 4-6 6-0 7-6 (7-1) first-round loss to Christina McHale.
Watson, 23, was beaten on a tie-break in the third set, despite a stunning comeback in the second.
World number 83 Watson also lost in the first round of the Australian Open last month - her most recent tournament.
British number one Johanna Konta progressed and will face Croatian Mirjana Lucic-Baroni in the next round.