Simona Halep is again one win away from delivering Australian coach Darren Cahill his third tennis world No.1 after cruising into the final of the Cincinnati Open.

Romanian Halep crushed American Sloane Stephens 6-2 6-1 in her semi-final and will face Wimbledon champion Garbine Muguruza in the title decider after Muguruza trounced world No.1 Karolina Pliskova 6-3 6-2.

Halep can displace Karolina Pliskova atop the rankings if she beats Muguruza on Sunday.

If she does, she will become Cahill’s s third charge to do so, after Lleyton Hewitt and Andre Agassi.

At 20, Hewitt became the youngest men’s year-end No.1 in history in 2001 under the South Australian.

Then Agassi, 20 months later at 32, became the oldest to reach the summit after linking with Cahill to resurrect his career.

Halep has yet to drop a set in the tournament and appears to be peaking at just the right time.

However, she has been in this position before.

Just over a month ago at Wimbledon she needed to beat England’s Johanna Konta in her quarter-final to reach the rankings pinnacle, only to succumb 6-7 (2-7) 7-6 (7-5) 6-4 in a thriller.

She feels she has the right form now to become the first Romanian woman to be ranked No. 1.

I think I played my best match on hardcourt so far,” said Halep, “It felt great. From the first point, I felt like I was going to play good tennis.”

Muguruza ended a run of six consecutive defeats against Pliskova, proving much stronger on serve than the defending champion to advance to Sunday’s final in less than 80 minutes.

“I was very precise with my shots,” Muguruza said.

“I wanted to be more aggressive and take my shots. I felt pretty good out there – under control. Everything went my way.”