Germany's Angelique Kerber celebrates as she moves into the Wimbledon finalGermany's Angelique Kerber celebrates as she moves into the Wimbledon final (AFP Photo/Daniel LEAL-OLIVAS)
Kerber took the express route to her a fourth Grand Slam title match with a 'blink and you miss it' demolition of Ostapenko on Centre Court.
The 30-year-old hit only 10 winners but that was all it took to get the job done as Ostapenko shot herself in the foot with 36 unforced errors.
Kerber faces seven-time champion Serena Williams or German 13th seed Julia Goerges in Saturday's final.
"I was just trying to move good and take my chances. I'm so excited," Kerber said.
"It's such a great feeling to be back in the final. Playing on Centre Court is always great."
Referencing her dismal form last year, Kerber added: "2017 is over and I'm really happy about that. We are in 2018!
"I'm really happy and proud to be in a Grand Slam final. These are the matches I was working for since I was a kid."
Kerber was beaten by Williams in the 2016 Wimbledon showpiece.
It will be world number 10 Kerber's first Grand Slam final since she won the second of her two major titles at the 2016 US Open.
Kerber is bidding to become the first German woman to win Wimbledon was Steffi Graf in 1996.
After winning the Australian and US Open titles and reaching the Wimbledon final two years ago, Kerber endured a significant slump in 2017.
But the former world number one has been reinvigorated over the last few months.
In her third Wimbledon semi-final and seventh at the majors, Kerber landed the first blow with a break, thanks to a wild Ostapenko misfire, in the seventh game of the first set.
Ostapenko's go for broke mentality came back to haunt the 12th seed again when a double fault on set point allowed Kerber to seize the lead.
Having dropped a set for the first time in the tournament, former junior Wimbledon winner Ostapenko was broken again in the second game of the second set as Kerber stepped up the pressure.
Ostapenko, 21, had admitted she cracked under the strain of defending the French Open title when she lost in the first round last month.
And the first Latvian woman to make the Wimbledon semi-finals was paying the price for more rash mistakes as the match slipped away.
Showing her first sign of nerves Kerber wasted a match point and was broken when she served at 5-1.
- Supreme Serena -
In Thursday's other semi-final, Williams aims to reach her first Grand Slam final since winning the 2017 Australian Open.
Title favourite Serena, seeded 25th, has won nine of her 10 previous Wimbledon semi-finals.
In only her fourth tournament since the birth of her daughter Olympia in September, the 23-time Grand Slam champion is bidding to win her first major title as a mother.
Williams, who missed Wimbledon last year due to her pregnancy, won the grass-court Grand Slam on her previous two visits in 2015 and 2016.
She is on a 19-match winning streak at the All England Club, with her last defeat coming against France's Alize Cornet in the 2014 third round.
At 36 years and 291 days, Serena hopes to become the third oldest female Grand Slam finalist in the Open era.
Williams is also chasing the chance to equal Margaret Court's record of 24 Grand Slams singles titles.
Goerges is the only one of the four semi-finalists still waiting to win her first Grand Slam title.
The 29-year-old had served more aces (44) and hit more winners (199) than any other player in the first five rounds.
But this is uncharted territory for Goerges, who was in her first Grand Slam semi-final after losing in the first round on her five previous visits to Wimbledon.