She'll also regain the top ranking next week for the first time in six years - beating Serena Williams' record of 5 years, 29 days between stints at No. 1 on the women's tour - in another benefit of beating the top-seeded Halep.
Former No. 1-ranked Wozniacki is potentially one win away from a breakthrough Grand Slam title after advancing 6-3, 7-6 (2) over Elise Mertens on Thursday.
With the win, Wozniacki plugs the only hole in her resume, as she won the WTA Finals last fall and had not only already been World No. 1, she finished as it in back-to-back seasons in 2010 and 2011.
However, it was Wozniackiwho showed the first sign of weakness in the set, her forehand losing its penetration as Halep broke for 5-3 despite appearing close to cramping. "I never cry, but this is an emotional moment".
"Thank you for being here and I'm hoping I'm finally going to get that Elle cover".
Halep saw off three against Lauren Davis in the third round - eventually winning 15-13 in the final set - and then saved another two against Angelique Kerber as she won the semi-final 9-7 in the decider.
The world number one was on the back foot and suddenly dizzy, and she called a medical timeout to have her blood pressure taken after holding serve to 3-2 in the second set.
"I've dreamt of this moment for so many years", said second-seeded Wozniacki after becoming the first player from Denmark to win a Grand Slam. I'm shaking right now. But, yeah, I'm really sad I couldn't win it. "When you go out there on Saturday, (today) you have everything to win".
But she did that in the first set of today's match via a tie-break, before Halep ensured that it would go the distance. I think what she stands for is obviously what makes it most special. Halep had two matches ahead of the final where she faced match points, while Wozniacki only had one encounter.
Since pulling out before her second-round match as defending champion at the Hong Kong Open with an elbow injury, everything has gone Wozniacki's way.
She was in her 43rd Grand Slam appearance and desperate to get off the mark. Kerber then saved two match points to level the set.
Wozniacki has won four out of six head-to-head meetings against Halep, but they have never played a Grand Slam match. If she ends up losing to a better Wozniacki on Saturday, it will not shake her. However, she expects to play another thrilling game like today. "I knew that if I can stay healthy and I work hard, my game is good enough for it". "Honestly, I think that's one of the most positive things about all of this", she said.
In Thursday's semi-finals, we managed to pick up another victor as Simona Halep managed to edge past the outright and pre-match market favourite, Angelique Kerber.