WTA

The first time Serena Williams and Venus Williams faced off on tour was in Melbourne in the second round of the 1998 Australian Open. That was 19 years ago. Venus won that day, 7-6(4), 6-1, but that match would kickstart a 27-match rivalry that would define both of their careers. On Saturday they will face off for the first time since the 2015 US Open quarterfinals, and it's a match that few ever thought they'd see again in a major final.

"This probably is the moment of our careers so far," Serena said, after her 50 minute win over Mirjana Lucic-Baroni in the semifinals. "For me, I can definitely say for me. I never lost hope of us being able to play each other in a final."

Serena has now made seven finals in her last 10 majors, and she's a win away from breaking Stefanie Graf's record of 22 major titles and returning to No.1. The World No.2 has not dropped a set all tournament and has navigated a difficult draw with ease. Gone are the signs of stress and anxiety that seemed to plague her at the Slams the last year.

"I think just going through that made me this way now, to be honest," Serena said of her new relaxed attitude. "I think sometimes when you're stressed out, you have to go through those moments. Everything creates a better you."

So while Serena's presence in Saturday's final was to be expected - she is, after all, a six-time champion at Melbourne Park - big sister Venus has been the surprise. Earlier in the tournament, the seven-time major champion admitted that she was anxious before the start of the Australian Open given injury concerns. In her first tournament of the season at the ASB Classic, she was forced to withdraw after the first round due to right arm pain.

"I mean, honestly, all the signs didn't look that way in Auckland," Venus said of her successful run. "Of course, I dreamed of it because I definitely worked hard in the off-season. It was not a great start, I'll just say that.

"But still I know I can play. You just have to try to figure it out if you can get it to line up all at the same time. That's why you get out and you try. As long as you continue to try, you have an opportunity. That's why I'm here."

To make her first Australian Open final in 14 years, Venus had to dig deep to fend off the overwhelming firepower from CoCo Vandeweghe. In blasting winner after winner in the first set, the younger American was able to bully Venus around the court with her heavy hitting. Venus couldn't stand toe-to-toe, power for power. And so she adjusted. She dug in. And used her brain and her speed to unwind Vandeweghe, who was playing in the biggest match of her young career.

"It felt very weird because I never do that," Venus said, referring to her defense. "Also, at the same time, I'm versatile. I can adjust. I can do what I need to do to win a match. I feel comfortable when I'm uncomfortable at the same time. Even if I'm in a position where I don't want to be at, it's not going to throw me off.

"I want to dictate, but the way she was playing, it was almost impossible to do so. So it was just about trying to control the point in whichever way that was. If that meant that defensively I controlled the point, or I was able to get a little offense, whatever it was. I mean, just be the one winning the point at the end somehow."

Indeed, after trying to outblast Vandeweghe in the first set, Venus began to go for less on her shots, using width and depth to get Vandeweghe uncomfortable. She cleaned up her errors. And most importantly, she had her best serving day of the tournament. Venus smartly handcuffed Vandeweghe with well-timed body-serves, and after seeing her second serve attacked in the first set, she decided to step it up.

"In the first set I served more conservatively," Venus said. "In the second, I just decided I was going to go for more. It was just really a mentality at that point. I know she's looking for a second serve. It's important to try not to give your opponent what they want.

"As the match went longer, the bigger I went on the second. Thankfully I was comfortable doing that and executing it and just going in. It worked."

In the end, the match was far more tense than the 6-7(3), 6-2, 6-3 scoreline might indicate. Vandeweghe earned 13 break points but was only able to convert once.

Venus' reaction on match point will go down as one of the most memorable, joyous, and redempting displays for the ages. One can only imagine what was flashing in her mind as the reality set in, that she was, for the first time since she was diagnosed with Sjögren's syndrome, back into a major final.

"I think why people love sport so much, is because you see everything in a line," Venus said. "In that moment there is no do-over, there's no retake, there is no voice-over. It's triumph and disaster witnessed in real-time. This is why people live and die for sport, because you can't fake it. You can't. It's either you do it or you don't.

"People relate to the champion. They also relate to the person also who didn't win because we all have those moments in our life."

Venus's ebullient celebration could serve as a Rohrschach test for any tennis fan. Do you see the 36-year-old champion, a woman who burst on the scene as a teenager over 20 years ago, showing her tenacity and quality to make a Slam final almost 20 years after making her first at the 1997 US Open?

Or do you see the player who fell out of the Top 100 after being diagnosed with an auto-immune disorder in 2011, who had every right to walk away from the game to pursue her other worldly pursuits, but battled back up to the top of the game by, seemingly, sheer force of will?

"I was always stressed out and worried if she would be okay and be able to play," Serena said. "I would see her practice, she'd practice so well, do so well. I always felt like when she lost, I was almost surprised, kind of like, How did you lose, because you're doing so well.

"At the same time I was like, Wow, it's amazing that you're even out here. I just really feel fortunate to have been there for the highs and the lows and everything."

Serena is the favorite heading into the final. As Venus said, her younger sister doesn't have many weaknesses to her game. While the match-up may look awkward from the outside -- No.23 and the No.1 ranking on the line and you have to go through...your own sister? -- Serena and Venus shrug it off. They've gone through this dance too many times to be distracted by the emotional resonance of their matches, whatever the stakes may be.

"After everything that Venus has been through with her illness and stuff, I just can't help but feel like it's a win-win situation for me," Serena said. "I was there for the whole time. We lived together. I know what she went through. It's the one time that I really genuinely feel like no matter what happens, I can't lose, she can't lose. It's going to be a great situation."

For Venus, it's just about the tennis. "When I'm playing on the court with her, I think I'm playing, like, the best competitor in the game," Venus said. "I don't think I'm chump change either. I can compete against any odds. No matter what, I get out there and I compete.

"So it's like two players who really, really can compete, then also they can play tennis. Then, okay, won't be an easy match. It's like I know that it won't be easy. You have to control yourself, then you also have to hopefully put your opponent in a box. This opponent is your sister, and she's super awesome.

"It's wonderful."