Allertova was having the best week of her career in Guangzhou - she not only took out the No.1 seed, Simona Halep, in the quarterfinals, her win over the World No.2 the biggest of her career, but she also followed that up with a semifinal win over No.3 seed Sara Errani to make her first WTA final.
She made a promising start in the final, too, getting broken in the first game but breaking right back and then holding for a 2-1 lead. But that's where all of it may have caught up with the young Czech.
The No.4-seeded Jankovic reeled off 11 games in a row from there, losing a total of just 20 points in those 11 games, to completely run away with the rest of the match, wrapping the victory up, 6-2, 6-0.
The former World No.1 fired one last ace out wide on the deuce side to finish Allertova off.
The two players stepped up to the podium for the traditional finalist speeches.
"It was an amazing time for me here," Allertova, who went first, said. "I'm so happy I could beat so many good players here and play my first final. Jelena was too good, but I'm happy with my week."
Jankovic gave Allertova all kinds of props when it was her turn with the microphone.
"Denisa, you had such a great run here in Guangzhou, beating such great players," she said. "And you played so well in the final - it was definitely closer than the result says. You'll have many more finals and many more titles in the future, so just keep going, just keep doing what you're doing."
This was Jankovic's first WTA title in more than two years - her last one came on the clay of Bogotá, Colombia in 2013. She did win a WTA 125K Series title in Nanchang, China this summer, though.
"It's amazing to win a title in China for the second time this year - obviously China is very special to me!" the Serb said to the crowd. "I really want to thank the fans, not just for today, but for supporting me for such a long time now, and coming out many, many years whenever I come to China."
How will she celebrate? "Actually I have to be in Wuhan soon, so I might not have time to celebrate!"
Jankovic now has 14 WTA titles to her name, her biggest coming at Indian Wells back in 2010.
And having saved a match point against Yanina Wickmayer in the semifinals, she's the sixth player this year to save match point en route to a WTA title (after Andrea Petkovic in Antwerp, Sara Errani in Rio, Daniela Hantuchova in Pattaya City, Camila Giorgi in Den Bosch and Belinda Bencic in Toronto).