US Open champion Sam Stosur beat Monica Niculescu 6-2 2-6 6-3 on Friday to reach the semifinals of the WTA’s Qatar Open.

The fifth-seeded Australian jumped out to a 5-0 lead in the first set, keeping the 31st-ranked Romanian off-balance with a solid serve and a powerful forehand. But Niculescu turned the tables in the second, breaking Stosur to go up 1-0 and then going up 4-1 before drawing level in the match.

Stosur regained the momentum in the third, jumping out to a 3-0 lead only to see Niculescu storm back to tie it. But Stosur then ran off the final three games to reach her first semifinal of the year.