Kerber had to fend off another break point in her next service game, but eventually got the job done to book her fourth career grand slam final.
After the brisk first set, Goerges competed much more effectively in the second until she saw her serve broken once more to give Williams the advantage.
Goerges, the 13th seed, was playing in her first Grand Slam semifinal. "These are the matches I was working for as a kid and to be in the final at Wimbledon is great".
She double-faulted on set point and Kerber, who served well and defended superbly when required to fend off Ostapenko's sporadic attacks, accelerated into a 5-1 lead.
Williams was back giving the crowd a one-arm raised victory twirl after reaching a 10th Wimbledon final after her opponent swiped a lob behind the baseline.More news: London awaits Trump's visit, braces for protests
For the second time in three years, Williams will face Angelique Kerber for the title.
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.
Ostapenko, 21, had admitted she cracked under the strain of defending the French Open title when she lost in the first round last month.
Serena Williams is back, for real.
"It is a great feeling to be in the final and playing on the Centre Court is always a great experience and I am really excited", she told the BBC.More news: Chelsea strike gentlemen's agreement with Napoli coach Maurizio Sarri
Williams, who missed Wimbledon a year ago 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.
Williams has won 23 Grand Slams, one shy of Margaret Court's all-time record of 24 singles Grand Slam titles. 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.
The 30-year-old was gifted point after point as Ostapenko's aggressive game backfired in a blaze of unforced errors.More news: Vertonghen 'gutted' after semi-final loss
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