Williams won her first of seven Grand Slams at Wimbledon in 2000, when Ostapenko was three years old.
Muguruza came into Wimbledon as anything but the favourite.
"I always stare at the wall where all the names are of the previous winners", Muruguza said. "So I have an opportunity to bank on experience in having dealt with those sort of pressures before". I'll have to see what's working.
The all-conquering American is absent this year as she prepares for the birth of her first child and the race to succeed her is wide open.
Williams' semifinal was more competitive, at least at the outset. Her most recent came in 2008, when she defeated her younger sister, Serena, for the title at the All England Club.
"I wasn't expecting anything because you never know how it's going to go". I'd like to think that I'm doing the same. She then broke twice to open the second set and take a 4-0 lead. The two had a fierce seven-shot exchange on the final point of that, until Konta's last gasp went into the corner, where it nearly hit both lines there but landed just beyond the baseline.
More belligerent tennis brought an immediate breakthrough in the second set, unrelentingly powerful and accurate strikes against Rybarikova being rewarded with a forehand from her crestfallen opponent that flew yards wide out of court.
It was Serena who beat Muguruza in the 2015 finale at SW19.
It will be Muguruza's second Wimbledon final.
Yes, the British No. 1 is upset at missing the final of her home Grand Slam.
Konta badly needed a stretch of points to get back in the fight, but she struggled to find the consistency of her earlier performances.
Williams was also very complimentary about her semi-final opponent Johanna Konta, who was hoping to become the first British female victor at the All England Club since 1977. A pivotal two games, however, decided the set and probably the entire outcome.
Williams erased the first break point with a backhand victor down the line, and the second with a 171 kph second serve that went right at Konta's body. On the second, an excellent 106-mile-per-hour second serve into the body gave Konta no chance.
"Konta played so well, no point was easy".
Konta, the first British female semifinalist since Virginia Wade in 1978, did not quite find the level that pushed her through a sequence of lengthy matches here, including a three-set quarterfinal squeak past No. 2-ranked Simona Halep.
But it was Williams who left as the victor on the day.
The subtle hand-skills and ball-control precision Rybarikova displayed throughout the tournament offered little resistance against the 2015 Wimbledon finalist's heavy, deep drives that pinned the Slovak behind the baseline.
"This match was complicated because she was playing well since the start of the tournament".