Semi-finalists at the World Cup 12 months ago, Croatia knew they would qualify for next year's European Championship in Germany with a win against Armenia in Zagreb, but any slip-up would have allowed Wales to leapfrog them into second place in Group D.
In the end it was a header two minutes before half-time by Ante Budimir that gave Croatia a 1-0 win to take them through, while Wales could only draw 1-1 with already-qualified Turkey in Cardiff.
Croatia's prospects of automatic qualification had appeared in doubt when they lost to both Turkey and Wales in October, but they become the 21st and final automatic qualifier for the 24-team tournament next June and July.
"We deserve to be at the Euro and we have a lot of time now to prepare for what awaits us there," veteran captain Luka Modric told UEFA.com.
Wales will now go into the play-offs next March to determined whether they qualify for a third consecutive Euro.
A draw this Thursday will decide whether they face Finland, Ukraine or Iceland in the play-off semi-finals.
A victory in that would set up a final decider against Poland or Estonia, with three qualifying spots in total on offer in the play-offs.
They beat Ukraine in a play-off to qualify for last year's World Cup.
Rob Page's side needed to beat Turkey on Tuesday to stand a chance of overtaking Croatia, and they went ahead through an early Neco Williams goal. However, Yusuf Yazici's 70th-minute penalty earned Turkey a draw.
"That level of performance is what we need to do. If we do that when we come back together in March we'll be ok," insisted Page.
- French denied late winner -
France missed out on finishing with a perfect record in Group B as they drew 2-2 with Greece in Athens.
Captain Tasos Bakasetas equalised for Greece soon after the break and Fotis Ioannidis then put them in front.
However, Youssouf Fofana's powerful strike pulled France level again, and they appeared to be denied a certain winner at the death when Kingsley Coman's deflected cutback seemed to cross the goal-line before spinning back onto the post and out.
But it was missed by the on-field officials, who had no goal-line technology to help them.
"This is the international level. There was no qualification at stake obviously but there could have been," French coach Didier Deschamps complained to broadcaster TF1.
"To have a ground with no goal-line technology -- because there isn't, because it's expensive -- obviously it is incoherent, but the officials have to put up with it," he said, adding that the VAR official could not give a goal if he was "only 99 percent sure" the ball had gone in.
- Dutch hit six -
Greece, the 2004 Euro winners, do not qualify automatically but can still come through the play-offs.
The Netherlands had already qualified from the same group before their 6-0 win over minnows Gibraltar in Faro, Portugal.
Romania and Switzerland had already qualified from Group I prior to their clash in Bucharest, which the hosts won 1-0 thanks to Denis Alibec's second-half goal.
Israel, who will be in the play-offs, won 2-0 in Andorra in the same group, while Belarus beat Kosovo 1-0.
The final draw for Euro 2024 will take place in Hamburg on December 2.