The question was whether Thelin's side could compete with the champions and send a signal that they might be capable of offering a serious title challenge.
On this evidence, the signs are very, very encouraging. There is a long way to go, of course, but Aberdeen fans left Celtic Park euphoric.
Their team started fairly brightly, but the script looked to be following familiar lines when they went two down. The response was magnificent.
Thelin talked pre-match about sticking to the identity and style they have been adopting and how the players would react if that was tested and they were put under pressure.
To come from two down was incredible. To have the chances to win it bordered on the unbelievable.
Yes, they rode their luck at times as Celtic frantically searched for a winner, but this was a statement performance and result.
For the doubters that presumed Aberdeen's start might be a fleeting foray to the higher regions of the Premiership, this display lends significant weight to the idea that they have a serious manager with a determination in his squad to succeed.