In an all-Chinese women's singles final in Hangzhou, Wang Zhiyi fought back from a game down to defeat Han Yue 19-21, 21-19, 21-11 in 74 minutes.
Shi beat Antonsen 21-18, 21-14 in 52 minutes to win the prestigious title for a second time in his career, to go with his triumph in 2018.
"Playing at home makes me very happy," said the 28-year-old Shi, who paraded around the venue after his victory and threw his shirt into the crowd.
"These people are very passionate and supportive," he added.
Antonsen's fellow Dane, the reigning two-time Olympic champion Viktor Axelsen, was not in China to defend his title after pulling out before the competition with injury.
There was home glory too for mixed doubles pair Zheng Siwei and Huang Yaqiong as they beat Malaysia's Chen Tang Jie and Toh Ee Wei in three games to retain their title.
It was a triumphant farewell to badminton for the 27-year-old Olympic gold medallist Zheng, who had announcement his intention to retire from the sport after the tournament.
South Korea's Baek Ha-na and Lee So-hee won the women's doubles and the Danish duo Kim Astrup and Anders Skaarup Rasmussen prevailed in the men's doubles final.
