They have not been dominant. They have toiled to victory against lesser opposition. They have looked at risk of being carved apart by fellow heavyweights.
On Thursday, the South Korean outfit take on J1 League opposition in the form of Urawa Red Diamonds in the East Zone semifinal -- with the victors marching on to next February's final, where they will lock horns with the West Zone's representatives for the title.
Urawa will head into the tie as favourites and it is easy to see why.
Apart from the obvious home advantage, Urawa have been rampant all campaign long even if their form has not been replicated on the domestic front.
The Reds were the top scorers in the group stage with 20 goals from six outings, and backed that up three months on with successive 5-0 and 4-0 routs over Johor Darul Ta'zim and BG Pathum United -- in the Round of 16 and quarterfinals -- to book their last-four berth.
What about Jeonbuk?
They only made it out of the group stage by virtue of being one of the three best-ranked runners-up after finishing behind Yokohama F. Marinos.
Come the Round of 16, Jeonbuk made hard work of an extra-time victory over compatriots Daegu, who currently lie eight places and 22 points behind them in K League 1.
If not for Kim Jin-kyu's dramatic 121st-minute winner, they could easily have been eliminated through the lottery of the penalty shootout.
Their game plan seems uninspired, their play at times borders on agricultural -- so how have Jeonbuk got this far?
Their secret to winning could simply be a refusal to lose.
Where they lack in the star quality of the Vissel outfit they saw off, or even the free-flowing gameplay of the Urawa side they will be coming up against, Jeonbuk have fight.
Lots and lots of it.
And that also stems from the amount of experience the two-time ACL champions boast in their ranks.
Modou Barrow is another that has tasted English football's top flight in his time at Swansea, Paik Seung-ho has previously plied his trade in both Spain and Germany, while Kim Jin-su and Moon Seon-min are seasoned internationals who featured for South Korea at major tournaments in recent years.
From early balls in behind opposition defences to regularly putting in deliveries from out wide to best exploit the strengths of Barrow, Gustavo and Song Min-kyu, Jeonbuk's football borders on 'route one' at times.
Although they do enjoy their fair share of possession, such a direct approach is exactly how they got all three goals in their triumph over Vissel.
There may be nothing pretty about it but it is pragmatic. And it has gotten them this far.
Perhaps the secret to Jeonbuk's success in the ACL so far this season is that there really isn't a secret.
Their football is simple and fuss-free. And they win simply because they refuse to lose.