Simona Halep has set up a Miami Open semi-final with world number one Serena Williams after beating Sloane Stephens in straight sets.

Stephens showed some promise in Halep's opening service game, hinting that she might provide a stern test to the Romanian.

However, an unforced error from a forehand gifted Halep a break of serve at the start of the first set and the world number three seized control with another break before winning it 6-1.

The 2014 French Open finalist underlined her dominance by breaking Stephens at the start of the second set and she managed to strike again to open up 3-0 lead.

Stephens, currently ranked 45 in the world, managed to roll off four consecutive games, to the delight of the majority inside the Stadium Court in Key Biscayne and give herself a chance of forcing a decider.

However, Halep managed to find a break in the 11th game of the set and served out 6-1 7-5 to seal last-four clash with Williams.