It shouldn't come as too much of a surprise that these two teams are battling it out for a spot in the final.
Japan are the only side to have won it four times while Iran are alongside Saudi Arabia the only team to have won it on three occasions.
They were among the favourites at the off and the pair of them continued to share favouritism with South Korea ahead of the knock-out stages. And the Betfair Sportsbook market thinks that whoever wins this is likely to go on and win the whole thing, with Iran just 6/5 to lift the trophy and Japan 2/1 second-favourites.
That's because Iran have arguably been the most impressive side here in the UAE. They thrashed Yemen 5-0 in their opening game, beat Vietnam 2-0 before playing out a bore 0-0 draw with deadly rivals Iraq after both were already through. They then beat Oman 2-0 in the last 16 and China 3-0 in the quarters. You will have noticed that they're yet to concede a goal.
Japan have been ok but wins by 3-2 over Turkmenistan and Uzbekistan by 2-1 in the Group Stages suggest all is not well in their defence. Although they did admittedly keep back-to-back clean sheets in their Last 16 and quarter-final matches.
The head-to-head between the two is pretty close with three draws and a win-a-piece in the five games they've played since 2000. It's not a great guide though because they've only played once since 2005, a 1-1 draw in 2015.
So a better indication of the quality of each side might be their FIFA ranking. Iran, so hard to beat the last World Cup, are 37th with Japan down in 61st so the evidence is that it's been Iran who have been in better shape over the last two years or so.
This is the stage of the tournament where things get really tight - three of the four quarter-finals ended 1-0 - and the smart money is Iran just edging it, so a win for them with under 2.5 goals at 13/5 looks the best bet.
Qatar can carry on winning without conceding
Qatar v UAE Tuesday January 29, 14:00
It's always a shame when the host nation goes out early but the United Arab Emirates have already done a fantastic job in making sure that didn't happen here.
They didn't pull up any trees in the Group Stages with a 1-1 draw over Bahrain, a 2-0 win over India and then a 1-1 with Thailand but have gradually been improving. They did no more than 'their duty' in knocking out Kyrgystan (3-2 after extra time) but saved their most impressive result for the quarters, beating defending champions Australia 1-0.
Qatar have mirrored Iran in reaching this stage of the competition without conceding a single goal. They won 2-0, 6-0 and 2-0 in the Group Stages, that last victory a particularly impressive one given it was over an always competitive Saudi Arabia.
They then followed that up with back-to-back 1-0 wins over Iraq and South Korea in their two knock-out games. Given South Korea were joint-favourites to win the Asian Cup going into that match, it was no small feat.
Their star man is Amoez Ali, who is the tournament's leading scorer with seven goals, including getting both in that 2-0 win over Saudi Arabia. He also got four against North Korea.
With Qatar not looking in any sort of trouble at any stage so far up against a UAE side who has made the most of home advantage but never looked in complete control, we have to side with the former.
You can take 6/5 on the straight 90 minutes win but you can also take 2/1 on them winning without conceding. Given it's been all clean sheets for them so far, that looks like a value punt.