It worked. The 11th-seeded Kerber reached her second final at the All England Club by avoiding too many mistakes and using a seven-game run to seize control for a 6-3, 6-3 victory over the 12th-seeded Ostapenko on Thursday.
Kerber, 30, lost in the 2016 final to Serena Williams - and the pair will meet again if the American beats Julia Gorges in the second semi-final.
Incredibly, with Williams serving for the match, Goerges broke back but it was a mere stay of execution as the mother-of-one broke again to advance to a 10th final.
"I am really happy and proud to be back in the grand slam final".
Goerges had come into her first Grand Slam semi-final having belted more winners (199), more aces (44) and more unreturned serves (113) than anyone else in the women's draw but those statistics counted for little when she came up against an opponent who is in hot pursuit of a record-equalling 24th major.
Williams took a 19-match Wimbledon winning streak into the day.
Williams, who missed Wimbledon past year due to her pregnancy, won the grass-court Grand Slam on her previous two visits in 2015 and 2016. She had 14 winners and 10 unforced errors, while Kerber had three winners and - this was key - zero unforced errors.
Eventually, Kerber's style ruled the day. Ostapenko's strokes were missing and she grew increasingly frustrated, slapping a thigh after a miss or leaning forward and putting her hands on her knees after others.
Having dropped a set for the first time in the tournament, former junior Wimbledon victor Ostapenko was broken again in the second game of the second set as Kerber stepped up the pressure.
The Latvian stuck to her guns, continuing to go all out at the start of the second set, but her radar was way off and Kerber quickly opened up a 3-0 lead, with one break of serve.
Kerber looked anxious and Ostapenko had a point to close to within a game but she dumped a backhand return into net and then coughed up two more errors to hand Kerber victory.