The right winger finished with aplomb in the 74th minute to send Spain 7-1 up after Nico Williams found him with a cut-back.
Yamal broke Barcelona team-mate Gavi's record by playing for the national team at 16 years and 57 days.
Gavi, who started against Georgia, set Spain's previous record in 2021 when he made his debut at 17 years and 62 days. He also held the record for youngest goalscorer, when he netted in Jun 2022 at 17 years and 304 days against the Czech Republic in the Nations League.
Yamal came on with Williams to replace Marco Asensio and Dani Olmo, who had both suffered knocks, after 43 minutes, with Spain 4-0 up.
The winger became Barcelona's youngest ever player to feature in La Liga in April when he came on as a substitute at 15 years and nine months for the Spanish champions against Real Betis.
Spain coach Luis de la Fuente selected Yamal after he started the season well for Barcelona, becoming the Spanish top flight's youngest starter in the 21st century in August.
"Lamine appeared very good to me watching him on television, but working with him you realise even more his potential. He seems even better," De la Fuente told a press conference Thursday.
"Currently, he's a very important player for us, he's here on his own merit. I have total confidence in him. I think he's a great player."
