Fifth-seeded Ernests Gulbis extended his winless streak this year to five matches Monday after losing to Denis Istomin 7-5, 6-2 in the first round at the Dubai Tennis Championships.
The 14th-ranked Gulbis, who was ranked inside the top 10 last year after reaching the French Open semifinals, led 4-1 in the opening set before falling apart.
"I'm not in good form right now," Gulbis said. "I'm not feeling my shots at all. I have no timing. In practice I have been playing worse than in the match."
Also, Joao Sousa of Portugal beat James McGee 6-1, 6-2.