Great Britain fell 1-0 behind in their Fed Cup World II play-off against Romania after Simona Halep defeated Heather Watson.
It was a tough task for Britain's number two against the world number five, playing a match at her home club for the first time since her junior days.
And, although Watson played very well in patches in the first set, Halep ultimately proved much too good and eased to a 6-4 6-1 victory.
Britain will now be relying on their own top-10 star, Johanna Konta, to bring the tie level when she takes on Sorana Cirstea, a late replacement for Irina-Camelia Begu, in the second rubber.
After rain, storm-force winds and even the odd flurry of snow had disrupted preparations for the tie in Constanta, the sun at last came out for the opening day of play.
There was still a bitter wind and Watson played the match in leggings.
Britain are looking to reach the elite level of the competition for the first time since 1993 and Watson recovered from dropping serve in the opening game to push Halep.
The 24-year-old has not had a good season so far, dropping to 113 in the rankings, but Fed Cup usually brings out the best in her and she likes clay.
A poor game at 4-4 was the turning point, though, with Watson dropping serve to love and then seeing Halep clinch the set in front of her enthusiastic home fans.
The second set lasted just 25 minutes as Halep reeled off the last five games, sealing victory when Watson netted a final forehand.
