(Shakir Hamzah 44, Khairul Amri 90+5)
(Fitri Shazwan 58)
Instead of folding after conceding a headed equaliser to the shortest player on the Jalan Besar pitch, they fought on with belief.
Instead of capitulating, they capitalised on their last attacking set-piece to slay the Red Giants with an injury-time winner.
Instead of dropping two points, defending Malaysian Super League champions LionsXII have delivered their first league win of the season and extended their unbeaten home record to 22 matches.
Big seasons are made of such memorable victories - think LionsXII's 1-0 away win at ATM FA last year - and LionsXII coach Fandi Ahmad believed this could be a defining moment for his team.
"Other coaches may be happy with a draw against a good team like Selangor when the game is into the 90th minute, but we wanted to go for the win," said the 51-year-old.
"We gambled, we pushed Safuwan (Baharudin) up, we brought on Shahfiq (Ghani) even though he is not fully fit, we kept (Khairul) Amri on even though he had a groin strain from the first game.
"And we kept believing we could get the winner, even deep in injury time, which we did.
"The boys showed great determination, discipline and teamwork.
"Maybe technically, we are not as good as some teams like Selangor, but we have the fighting spirit and we hope to build on this big, morale-boosting win."
Much of the pre-match hype was centred on Selangor's fearsome attack, spearheaded by Brazilian duo Paulo Rangel and Juninho and augmented by speedy wingers S Kunanlan and Fitri Shazwan.
But they were kept on a tight leash by LionsXII's defensive trio of skipper Isa Halim and centre backs Afiq Yunos and Safuwan Baharudin.
Left back Shakir Hamzah also had an outstanding game shackling Kunanlan, so much so the Selangor right winger had to switch flanks with Fitri to try to gain inroads.