World No.1 Serena Williams marched into the semi-finals of the Western & Southern Open with a straight-sets win over Simona Halep.
Williams, bidding for her ninth title of the season, came through 6-0 6-4 in an hour and four minutes and will take on defending champion Li Na in the last four.
The American broke her unseeded opponent three times in a row while taking opening set in 16 minutes.
Halep - the world No.25 from Romania - improved in the second set and managed to break Williams' serve.
But Williams added two more breaks of her own to close out a result that improves her overall record for the year to 59-3.
Fifth seed Na had a walkover in her quarter-final against fourth seed Agnieszka Radwanska, who withdrew from the tournament to return home for the funeral of her grandfather.
In the other half of the draw, Serb Jelena Jankovic will take on second seed Victoria Azarenka for a place in the final.
Jankovic, the 14th seed, saw off 12th-seeded Italian Roberta Vinci 6-0 6-4, while Belarussian Azarenka overcame 10th seed Caroline Wozniacki 6-3 7-6 (7/5).