MADRID, Spain - No.3 seed Simona Halep's supreme claycourt form continued at the Mutua Madrid Open as she swept into her fourth final here, and first of 2019, in one hour and 57 minutes with a 6-2, 6-7(2), 6-0 triumph over the unseeded Belinda Bencic.

"It is normal at this level, I expect tough matches all the time," Halep said to the press, following her first three-set match of the tournament. "I was lucky that during the week I had short matches. But always when I step on the court I'm ready for a three-hour match, so I'm okay."

Read more: Stat Corner: How Simona Halep played the perfect match in the most dominant win of her career

The Romanian had not beaten Bencic since their first meeting in the third round of Wimbledon 2014 - and in fact had been a victim of the Swiss player en route to two of her three career titles, with Bencic taking wins in the 2015 Toronto final and the Dubai quarterfinals this February.

But today, Halep was on her home turf of her beloved clay at a tournament she has won twice previously, in 2016 and 2017 - and for much of the day played the match on her own terms to emerge with her 25th victory in Madrid. The result also puts Halep just one win away from retaking the World No.1 ranking for the first time since Naomi Osaka dethroned her in January.

"All the time when I come to the clay court season, there is an extra motivation and I feel better," said reigning French Open champion Halep.

"I found Simona was playing better than me the whole match," Bencic told the media, following the clash. "But overall, I’m pretty happy how I fought. I found that I defended pretty good. It was opposite today, I was mostly the defense, and Simona was the aggressive one, so I think that makes the difference as well."

A cagy opening sequence in which both players were still finding their rhythm saw first Halep break and move into a 2-0 lead, then get pegged back to 2-2 by the World No.18. At this point, though, the Roland Garros champion put her foot down. Racing through 20 of the next 24 points, Halep reeled off five straight games to go up a set and a break.

Gallery: Magic in Madrid: Halep, Bencic, Stephens and Bertens seal last-four spots

Demonstrating impeccable depth and accuracy from the baseline, the 27-year-old smothered her opponent with ruthless efficiency, nailing breathtaking down-the-line winners off both wings after working all angles of the court. By the end of the set, Bencic was tactically at sea, having only found success on the rare occasion she had been able to find her way into net to put away a drive volley.

Playing her first claycourt semifinal since her maiden appearance in the last four of any WTA tournament at Charleston 2014, Bencic had a stellar junior career on the terre battue, winning Roland Garros juniors in 2013 - but is still learning to love it as a pro. That process took another step forward as she fought back in the second set, halting the Halep juggernaut with some precise, deep hitting of her own - as well as taking some frustration out on the Halep second serve.

Read more: Belinda Bencic learning to love clay: 'Sometimes I figure it out, sometimes not'

Backhand winners sealed consecutive games as the 22-year-old ran off a three-game streak of her own - and though an ill-advised dropshot attempt found the net to relinquish the lead, Bencic had got a foothold firmly in the match - setting the scene for a narrowly, often brilliantly contested second set.

The climax of the set found the Dubai champion needing to maintain her composure as a number of half-chances passed her by. Two points from the set at 5-4, Bencic's backhand let her down, and her racquet went flying; at 6-5, a breathtaking forehand down the line brought up a set point, but Halep came up with some of her most authoritative tennis to escape it and hold. But despite these setbacks, Bencic kept a cool head to dominate the tiebreak, starting by maintaining a perfect record at net with her 12th and best volley of the day.

"I think I was rushing a lot in the tie-break, the first point, and when I saw it was 4- 0, I lost confidence a little bit," said Halep. "But then I just repeated to my head that the match is starting now, so I have just to focus on the last set, not thinking anymore about the second set.

"Also, I analyzed a little bit what I did wrong in the second set, and I was sure that I have been too far back from the court, and [Bencic] had a better chance to open the court and to dominate the game. So then I just said that I have to push her back a little bit more and to stay closer to the baseline, which helped me a lot."

In the decider, it was Halep's turn to shake off her troubles as she brought back her first-set form with a vengeance. The former World No.1's forehand was particularly ferocious, both as the full stop to extended baseline exchanges and as a dismissal of the Bencic second serve; as for her own serve, it was at its most efficient, with Halep even holding to love for 3-0 with three unreturned deliveries and her sole ace.

Bencic, meanwhile, paid the price for some slight lapses in concentration. Twice at the crucial end of a game, the former World No.7 essayed a good dropshot - only to make a mess of the putative putaway follow-up. As the set fell all too rapidly away from an increasingly distressed Bencic, Halep accelerated towards the finishing line with relish, breaking her opponent for the third time in a row and sealing victory on her first match point when a Bencic backhand found the net.

Halep's fourth bagel set of the tournament follows her 6-0, 6-4 first-round defeat of Margarita Gasparyan and her 'perfect' 6-0, 6-0 third-round rout of Viktoria Kuzmova, and sets up a final against either No.7 seed Kiki Bertens or No.8 seed Sloane Stephens.

"They feel the ball really great here on clay and it's going to be a massive match because they have also confidence," Halep said of both of her potential final opponents. "We are the same level of confidence, I think."

"I think they are great players," Halep stated. "That is why they are in the top. So there is nothing weak that I can say about them. So it's just a very tough level where we are and we have to enjoy it because we work for that."