It was one of the biggest crowds to watch a round-robin premier club rugby match in Dunedin for more than 40 years.
''I know there is good support for Taieri and Kaikorai but I guess a few people came out to see how the old man played and how he keeps going,'' Thorn smiled.
It was a special day for Thorn. He was born in Mosgiel and was 4 when he watched his brother Aaron play for the club. The family then shifted to Bannockburn before moving to Australia.
Thorn has had a distinguished career, playing league for the Brisbane Broncos and the Kangaroos, and rugby for the Crusaders, Canterbury, Tasman, the Highlanders and the All Blacks, for whom he played 60 games.
But he also had a hankering to play for Taieri.
''It was a pretty emotional day for me,'' he said.
''My uncle, Robin Gamble, handed me my Taieri jersey in front of the team and said some very nice words.
''It was a special moment for me. My father [Lindsay Thorn], my brother [Aaron] and most of my relations played here. It is special for me to join the club and be part of it.''
Thorn is not sure if he will play any more games for Taieri.
Thorn made an impact on Saturday with his strong scrimmaging and his work in the tight. But he also had one flashy moment when he flung a back-handed pass out to the wing.
''I played with Sonny Bill [Williams] for a couple of seasons and learned a few tricks,'' he said.
''The Kaikorai boys and the Taieri lads can be very proud. It was a good standard of rugby.
''It was just nice to be out there with both teams and with boys who have a passion for rugby.''
Taieri beat Kaikorai 43-18 to remain at the top of the Gallaway Trophy competition.