Garbine Muguruza annihilated Simona Halep to claim the Western and Southern Open and deny her opponent a place at the top of the WTA rankings.

Halep came into Sunday's final in Cincinnati knowing victory would see her overtake Karolina Pliskova - beaten by Muguruza in the semis - and become the 24th woman to become world number one.

But after already missing out on two previous occasions to rise to the top this season, Halep was never given a sniff by Muguruza, who romped to a 6-1 6-0 victory.

This Premier 5 title represents Muguruza's second tournament win of the year, following on from last month's triumph at Wimbledon, and was just reward for a performance brimming with confidence.

Muguruza had staved off three match points in the last 16 against Madison Keys and had come through a three-set tussle with Svetlana Kuznetsova in the quarters but there were no such hiccups in the final as she left Halep devoid of answers.

Halep came into this meeting having not dropped a set in the tournament, but she was under pressure immediately and a forehand into the net gave Muguruza a break and a 2-0 lead.

The Romanian was unable to find any form as a double fault handed her opponent another break and a 5-1 advantage before a return flew long in the next game and Muguruza took the set.

And the Spaniard picked up where she left off at the start of the second as Halep continued to err on the forehand side, Muguruza clinching two breaks to move 3-0 ahead.

Muguruza was forced to save two break points in a lengthy fourth game, leaving Halep swiping her racket in anger.

And that frustration was exacerbated immediately as the fourth seed broke again to end any last vestige of hope for Halep, who was left to rue another missed opportunity to ascend to the summit of the women's game.