Once you do that, you've got a chance, but she wins points so quickly: "serve and next shot or else just a straight return victor", Navratilova said.
The American former world number one overpowered Germany's Julia Gorges 6-2 6-4, while Kerber beat Latvia's Jelena Ostapenko 6-3 6-3.
She's here to win it, in only her fourth tournament back after pregnancy, childbirth and a host of complications in the aftermath.
She will now contest a rematch of the 2016 final against German Kerber.
Bryan has won three Wimbledon titles with his brother Bob, who is absent with a hip injury. And some had her as the favorite even before it began. Kerber allowed Ostapenko to express herself and did not dictate much in the entire game.
"It's like, "C'mon guys, this is pretty awesome". She dropped out of the top-20, failed to make another Slam final and fired her longtime coach. "But when I wasn't a favorite, I was kind of upset about that".
"I had a real tough delivery and had several operations".
Here is a look at the main talking points ahead of Saturday's match.
She was silent - as was everyone on her team - save for a few instructions to hitting partner Jarmere Jenkins. I want to get as many as I can. She's also the lowest-ranked woman to reach the last four.
Pulled out her very best - again " I don't know what I expected from this tournament. "I'm just enjoying every moment".
"I was just trying to move good and take my chances. It is is the match I was working towards as a young kid".
"It's insane. I don't even know how to feel". But today was tough, as well. I think that's what I was doing in the past, I was limiting myself. I think she's incredibly confident.
"I'm glad no one told me at the time I was going through that".
Wimbledon 2018 -- Angelique Kerber advances to final
"It's insane. I don't even know how to feel because I literally didn't expect to do this well in my fourth tournament back in 16 months", 25th seed Williams said after beating Julia Goerges in the semis. "But overall I'm not frustrated about the way I hit".
"To be perfectly honest, I haven't thought about that this tournament".
But perhaps the most telling aspect of Williams' return is the mental application demanded of a woman whose dedication to the sport was once - mistakenly - considered suspect.
Kerber easily dismissed first-time Wimbledon semifinalist Jelena Ostapenko in the first semifinal.
However, the 14 errors meant that Kerber, at the third attempt, broke to lead 4-3.
Despite Andy Murray's absence and the failure of any British singles players to make it to the second week, the host nation will be represented right until the end of Wimbledon.
Still, it was a great tournament for Ostapenko, as it was for Goerges. The American won it, but it was a tight, competitive final.
When Williams took a leave of absence to have her first child soon after claiming her 23rd Grand Slam at the 2017 Australian Open, it appeared her streak might be under threat.
The world No 10, Kerber, is the only woman to have reached the second week of every Grand Slam so far this season. That is the kind of mistake Kerber can not afford to make again Saturday, when she faces Williams for the eighth time in her career, and only the second time on grass. Williams just wasn't able to give that second serve the pummelling it deserved.
2 - of the semi-finalists have won titles this year: Goerges (Auckland) and Kerber (Sydney). So is the rest of her game. She covered the court so well with speed and effort and seemed even better from previous rounds. "I've played tennis for over 30 years, so I'm so used to [being] incredibly fit".
For Kerber it is a second opportunity to win Wimbledon in a final after she reached the showpiece match in 2016.
"She knows the feeling to (go) out on this stage where you are in the finals, especially here". I had to have multiple surgeries and nearly didn't make it to be honest.
I hope Man Utd are chasing Messi and Ronaldo heir, Kylian Mbappe
It's a insane thing, we don't even dare to think about what is happening in France ". It's been a tough period, but it's been lovely to work for the lads.