Porte was chasing the breakaway spearheaded by Kwiatkowski when he suffered a front tyre puncture – his second blowout of this year’s Tour. The last Australian to finish on the general classification podium was Cadel Evans after his 2011 victory.
His Trek-Segafredo team reached him with a new bike but he fell back by 45 seconds before staging his remarkable recovery, reeling in the pack again 9km from the finish.
“I didn’t know Richie Porte had a puncture,” said Tadej Pogacar (Team Emirates), one of two likely contenders for the yellow jersey alongside Slovenian countryman Primoz Roglic and part of the pack chasing the Pole.
“We knew he was dropped… but now I know and I’m glad he came back because it would have been unfortunate had he lost his place due to bad luck.”
Kwiatkowski and Carapaz were the strongest in the breakaway in the 175km mountain trek from Meribel and the former did most of the work to help the Giro d’Italia champion crest the day’s summits in first place.
When it became evident they would not be caught by chasing riders and the peloton, the Ineos-Grenadiers duo had to discuss how the finale would pan out.
“I would have preferred to sit down and discuss it over a coffee but it was not possible,” said Kwiatkowski, who dedicated his win to former sports director Nicolas Portal, who died suddenly earlier this year.
“It was kind of chaotic but you know, for today the first goal was to collect points for the mountains classification and when we knew he was going to have it he basically said that I could have the stage.”
Both crossed the line together, with Kwiatkowski just centimetres ahead after a pat on the back from his teammate.
Kwiatkowski’s victory gave Ineos-Grenadiers something to cheer on this year’s Tour after their leader and defending champion Egan Bernal abandoned the race on Wednesday.
“I just believe that when you’re in the greatest team in cycling, expectations are very high, there is always a matter of winning and (this year) the GC (general classification) went away,” said Kwiatkowski, whose tireless work helped Chris Froome, Geraint Thomas and Egan Bernal in their successful campaigns from 2016-19.
“For many years I was trying to be in the winning team. Some years it means you’re in the squad of the yellow jersey in Paris and this year we’ve been trying to win a stage in the last week.
“We just always come out being successful out of the Tour. I’m proud of this team, I’m proud of us that we delivered it.”
Kwiatkowski will now do what he can to help Carapaz keep the polka dot jersey, although most of the job will have to be done by the Ecuadorian himself in Saturday’s individual time trial.
“The condition for me to have the win was that he gets the polka dot jersey in Paris,” said Kwiatkowski.
“Now I need to make sure he has it and I’m ready to help him defend that polka dot jersey. Maybe I can’t celebrate tonight then.”
Friday’s 19th stage is a 166.5-km undulating ride between Bourg en Bresse and Champagnole.