Girmay became the first black African to win a stage on the Tour on the third day of this year's edition in Turin and was first again on stage eight.
The 24-year-old then proved fastest in a bunch sprint finish on stage 12, as he topped the podium ahead of Wout van Aert and Pascal Ackermann.
Asked if he was comfortable as a role model, Girmay said: "Cycling is not a global sport yet, so for African cycling this (his stage wins) is a good thing.
"Now maybe the European teams may take more Africans. For now I'm the only one and I wish there were more black riders in the peloton," he said.
"I'm in the best shape of my life. I get up every morning and look in the mirror and tell myself to live the day.
"To win three stages in one race is wonderful. After the last win I had nearly 600 messages from home," he said.
Girmay now has 328 points to Jasper Philipsen's 217 with few real sprint stages remaining, with the exception of Friday's stage.
Roglic in costly fall
Title pretender Primoz Roglic provided the shock of the day as he fell further behind and seemingly out of contention for the title.
He had been fourth overnight but trailed home 2min 27sec behind Girmay after a fall that left his shoulder bleeding.
Roglic started the day 2min 15sec adrift but looked haggard as he crossed the line after struggling home over the final 12.5km.
The fall happened outside the zone where late crashes are overlooked for overall times.
An Astana rider failed to see a slender traffic island and took down around a dozen riders.
Overnight leader Tadej Pogacar remains 1min 06sec ahead of Remco Evenepoel in second, with Jonas Vingegaard in third, another 8sec behind.
Pogacar's thoughts were for his compatriot Roglic.
"I heard the crash but didn't look round. I was shocked by the bad news," he said.
"I'm really disappointed for him. It really sucks. I hope he can carry on. We know he's a big fighter."
When asked about his thoughts on being beaten to the line Wednesday by Vingegaard, he said he was happy in his yellow overall leader's jersey.
"I'm comfortable in the lead. It's up to him to attack if he wants the lead," said the 2020 and 2021 champion.
Pogacar's team-mate Joao Almeida is now fourth in the overall standings, with Ineos rider Carlos Rodriguez in fifth.
Evenepoel, the wearer of the white jersey for the outstanding young rider, said he had been extra careful.
"We knew there was a lot of road furniture in the final stretch, it's tricky. Better to stick to the front," said the Quick Step man.
The Tour lost two further participants on Thursday. First, bulky Belgian sprinter Fabio Jakobsen found it too hard to keep up with the swift pace and fell off the back to retire.
Spanish rider Pello Bilbao was also ill in the 33 degrees Celsius (91.4 Fahrenheit) heat and pulled out half-way through the stage.
Jonas Abrahamsen is level with Pogacar in the mountains classification on 36 points.
However, the Slovenian is the nominal leader due to his higher standing.
Stage 13 is one of the last obvious sprint stages on a flat run Friday from Agen to Pau, the gateway to the Pyrenees.
"Between Pau and Nice there is hardly any flat terrain at all," said route architect Thierry Gouvenou.
