Great Britain went 1-0 down in their Fed Cup World Group II play-off in Romania after Heather Watson lost 6-4 6-1 to Simona Halep.
World number five Halep increased her intensity at 4-4 and broke Watson to love before serving out to take the opening set for the hosts.
Watson, ranked 113, struggled to cope with her rival as she lost her serve twice to love in the second set.
GB's Johanna Konta plays Sorana Cirstea in Saturday's other singles match.
More to follow.