Second seed Halep crashes out of US Open
Simona Halep of Romania serves to Mirjana Lucic-Baroni of Croatia during their 2014 US Open women's singles match on August 29, 2014 in New York - by Kena Betancur
Lucic-Baroni, who came through qualifying, fired 31 winners past the 22-year-old world number two, breaking her five times to seal the victory in an hour and a half.
The 32-year-old next faces Italy's Sara Errani for a place in the quarter-finals. Errani, the 13th seed, held off two-time champion Venus Williams 6-0, 0-6, 7-6 (7/5).