David Weir admits Rangers' 4-1 defeat to St Johnstone was a major lesson that the Scottish champions must learn from as they bid to retain their crown at the earliest opportunity.
The Ibrox side headed for McDiarmid Park hoping to make the rearranged game in hand count by moving 13 points clear of rivals Celtic in the title race.
Instead, they were left reeling by an impressive Saints side who — despite only winning promotion to the Clydesdale Bank Premier League last year — are now on course for a top-six finish.
A blistering start saw the home side race into a two-goal lead thanks to efforts from Cillian Sheridan and Chris Millar, before Sasa Papac pulled a goal back to hand Rangers hope of a comeback.
But any thoughts of returning to Glasgow with the points were shattered when Liam Craig netted a third for the Perth outfit before the interval and Murray Davidson came off the bench to seal the win late on.
Rangers host Hamilton in the SPL this weekend and Weir's message was a simple one: Must do better.
“What happened here is a wake-up call for us and now we've got to use it as that,” said the Gers skipper. “We've got a lot of work still to do in the title race. This is a reminder that, if we're not at our best, we can lose and this has to be a big lesson for us.”
Weir became the oldest player ever to play for Rangers as he took his place at the heart of the defence 41 days short of his 40th birthday.
But what should have been a memorable occasion quickly turned into a night to forget for the veteran defender.
Reflecting on Rangers' heaviest ever defeat to St Johnstone, Weir said: “Although I don't know if 4-1 is a fair reflection of the match, I don't think anyone can claim we deserved anything from it.”