MELBOURNE, Australia -- In a battle between two-time Grand Slam champions and former World No.1 players, Garbiñe Muguruza continued her return to her peak form with a 7-6(8), 7-5 semifinal upset of No.4 seed Simona Halep of Romania, advancing to the fourth Grand Slam final of her career -- and her first at the Australian Open.

"Definitely the mission is to get away from here with a big trophy," Muguruza told the media in her post-match press conference. "Big or small celebration, it's incredible achievement. It really depends of how you're feeling. I believe in myself that I have what it takes to play these kind of matches and to be in this stage."

Muguruza led the head-to-head with Halep 3-2 coming into their semifinal clash -- with a pristine 3-0 record against the Romanian on hardcourt. As temperatures touched 38C/100F, it was Muguruza who once again came through on the surface, gritting out two grueling sets after just over two hours of play.

"I had a tough opponent," said Muguruza. "I knew it was going to be a tough semifinal against Simona. She's a very good player. Every time we played, it was very physical, long matches. I knew it was going to be a very hot day."

Muguruza, the 2016 Roland Garros and 2017 Wimbledon champion, powered her way to the tight two-set victory over Halep, the 2018 Roland Garros and reigning Wimbledon titlist. Muguruza shot 39 winners, including ten well-timed aces, to Halep's 20. Moreover, the Spaniard often used the tactic of rushing the net, and it paid off two-thirds of the 30 times she charged into the forecourt.

"It's tough to say really what's the little difference," Muguruza stated. "I guess maybe structuring better the points, using more my weapons. It's literally, like, a half-second or one shot the difference. It's very delicate. It's also a lot about confidence, the way you're playing. Yeah, just a mix of that."

The Spaniard, who held the World No.1 ranking for four weeks in 2017, had seen her form dip since, and came into the event unseeded and ranked outside the Top 30. Muguruza had struggled in her opening matches of the fortnight -- dropping her first set of the tournament 0-6 against Shelby Rogers -- and had withdrawn from Hobart the week before due to a viral illness.

Nevertheless, with new Hall of Famer Conchita Martinez back in her corner as her full-time coach, there had been good signs from Muguruza in 2020 before the illness struck, reaching the semifinals in Shenzhen and the quarterfinals in Hobart. Now, after playing her way back into health in Melbourne, Muguruza is 11-1 on the year and has guaranteed herself a return to the WTA Top 20.

In her first hardcourt Grand Slam final, Muguruza will attempt to win her third major title against No.14 seed Sofia Kenin of the United States. 21-year-old Kenin shocked World No.1 Ashleigh Barty in two tight sets in the earlier semifinal to advance to her first-ever Grand Slam final.

"I think [Kenin is] playing great," said Muguruza. "I think since a while she's just progressing up in the rankings and in the results. So I think she deserves to be in the final with the tennis she has been showing."

Muguruza lost her only prior meeting with Kenin, which came in Beijing last year, and the Spaniard admitted that it "wasn't a very good match from my side. I think she played good. It was the first time we played, so it was good to have that match as a reference. I mean, it's going to be a hard match. It's the final of a Grand Slam. Doesn't matter who is your opponent."

As for Halep, she told the press, after the match, that "to lose like this hurts more, definitely. I'm in pain now, I have to admit. But life is going on."

"I think maybe I could be a little bit more brave in the points that were important," said Halep, who will return to World No.2 after the event. "I didn't do that. Maybe I went a little bit defensive in those balls and I couldn't take the domination of the point."

With Muguruza rushing the net and Halep grinding out groundstrokes in the early going, both players were in top form, each saving two break points as they hustled to 3-3. Muguruza, though, took the early advantage in the opening frame, firing forehand winners to hold for 4-3, then earning the first break of the day with a backhand winner to go up 5-3.

With her back against the wall, Halep stormed back, holding at love to stay within touching distance at 5-4, then coming out on top in rallies to break Muguruza at love for 5-5. After a quick hold for 6-5, Halep was back in front, having won 12 of the last 13 points.

The Romanian’s momentum continued in the following game as great depth of shot garnered her two set points, but Muguruza slammed an ace to save the first, then outhit Halep during a stirring rally to erase the second. More aggressive forward thinking from the Spaniard allowed her to eke out the hold and send the first set into the tiebreak.

In the breaker, Muguruza jumped ahead 3-0 before Halep took the next four points. However, after two errors by Halep, Muguruza got to 5-4, then hit a big serve to force a wide return and go up 6-4, holding two set points of her own. Halep, though, kept the tiebreak rolling, saving both, the second with a bold and beautiful forehand winner down the line, leveling again at 6-6.

Muguruza then saved a third set point at 7-6 with a big serve, but a double fault gave Halep a fourth chance at 8-7. But Halep misfired on a wide forehand in a rally to miss that chance, and then blasted a backhand long to give Muguruza a third set point at 9-8. There, the Spaniard clinched the set, after her dropshot led to a speeding Halep finding the net with a forehand.

"You didn't know who was going to win that first set," said Muguruza. "The first set was very long, so I knew it was going to be key to the match because of the circumstances and the weather and everything. Just hang in there and whoever was going to be stronger was going to get it. I was happy that I stay solid there, took my chances at the end."

Halep twice went up an early break in the second set, and after consolidating for 4-2, the fourth seed was edging ever closer to forcing a decider. The Muguruza serve was clicking, though, which helped her erase many of Halep’s chances. With Halep serving for the set at 5-4, the Spaniard took her shot, converting her fourth break point of the game after a series of strong groundstrokes.

"[Muguruza] served very well in the important moments," Halep stated. "My return was not great today. I think it was a good match for both of us, but she was stronger in the end. In the important moments she played a little bit more braver."

Now level at 5-5, Muguruza used outstanding footspeed to take the edge in rallies, and after a quick hold for 6-5, the unseeded player crunched returns to pull ahead in Halep’s next service game. At that juncture, a Halep dropshot was returned with a winning Muguruza dropshot to set up double match point, and on the second one, another Muguruza dropper forced an error to seal victory.

2020 Australian Open Highlights: Muguruza seals final spot with win over Halep