A frustrated Serena Williams clawed into her 10th Miami final on Thursday, defeating Simona Halep 6-2,4-6,7-5.

Williams, apparently rattled by the Halep cheer squad who drowned out most of the chants for the home hope, saw her mighty forehand desert her in the second set, in which Halep converted the only break point of the set to force a third.

World number one Williams, who captured her 19th Grand Slam title at the Australian Open this year, regrouped to seize a 5-2 lead in the third only for the world number three from Romania to battle back.

Finally Williams found a way, and she will bid for an eighth Miami title against Carla Suarez Navarro.

Spain's Suarez Navarro earned her place in the biggest match of her career with a 6-3, 6-3 victory over Germany's Andrea Petkovic.

"I was barely able to regroup," admitted a relieved Williams. "I was making so many errors and was so frustrated.

"The only thing that was working for me was coming to the net. I'm just happy to get through this one.

"Still, it was actually a fun match, I'm in the final so that's unbelievable."

Williams has won all four of her matches against Suarez Navarro without dropping a set.