Once again, one of the great upsets in Champions League history felt sort of inevitable.

As Ajax chased the winner against Juventus in the second half of Tuesday’s quarterfinal return leg, its dominance of the Italian juggernauts in Turin was so comprehensive that the liberating away goal, which would require Juve to score twice to advance, felt like a matter of time. Matthijs de Ligt’s header in the 67th minute, finally making it 2-1 to Ajax and turning the aggregate score to 3-2 in Ajax’s favor, followed a handful of fat chances.

The goal that sent Ajax to its first Champions League semifinals since 1997 – when it lost to … Juventus – wasn’t just deserved, it was overdue.

Which is more or less what happened on March 5, in the second leg of the round of 16. Ajax slayed back-to-back-to-back champions Real Madrid 4-1 in the hallowed Santiago Bernabeu then, and it all felt like little Ajax had been merciful, somehow.

This isn’t supposed to be possible in the economic landscape of present-day soccer. The spending power of Juve and its ilk dwarf that of Ajax, and in soccer, you’re only supposed to as good as your transfer budget and your payroll.

But this oh-so-youthful Ajax has been so fearless in its high-pressing, all-out-attacking soccer that it’s rocked one giant of the club game after another – recall that Ajax twice outplayed Bayern Munich in the group stage. These victories over the winners of four out of the last Champions League five editions (Real Madrid) and the losing finalists in 2015 and 2017 (Juve) were no fluke. They were well deserved.

And so Ajax deserves to be among the four best clubs in Europe, playing to reach the club’s seventh Champions League final and a fifth European crown against the winner of Tottenham and Manchester City in the semifinals in two weeks.

But the resurgence of Ajax and the validation of its philosophy, prizing positive soccer before all else, was also an indictment on the star man on the other side of the field, Cristiano Ronaldo.

When Juventus spent some $135 million on a transfer fee, commissions and solidarity payments to lure Ronaldo from Real Madrid last summer, it didn’t do it to win Italy’s Serie A. It had already done so for seven years in a row. It didn’t need him for that.

It also didn’t commit more than a third of a billion dollars, between those fees and his $64 million-ish annual salary over a four-year contract, to leverage the world’s most-followed athlete into becoming Italy’s biggest club, or a global brand. Juve already was those things. It didn’t need him for that.

The 32-time Italian champions – or 34, if you count the two titles stripped in the wake of the Calciopoli scandal, as some do – didn’t gamble on a 33-year-old to fill a stadium. Never mind that the metrics show a typical soccer player’s prime is in his mid-20s, especially when he’s played a lot of senior team soccer as a teenager, like Ronaldo did. Never mind that Ronaldo was eight years older than the only three transfers in history more expensive than him. Juventus has never struggled to pack its gleaming Allianz Stadium, the nicest venue in Italy. It didn’t need him for that.

Nor did Juve really need Ronaldo to fill some hole in the lineup. In Paulo Dybala, Mario Mandzukic, Federico Bernardeschi, Douglas Costa and teenage prodigy Moise Kean, it already packed plenty of attacking firepower. In fact, Ronaldo’s arrival created a surplus, meaning the club had to offload star striker Gonzalo Higuain, discounting him to about a third of the club record, $100-million fee it had spent on him just two years earlier.

What Juventus needed Ronaldo for – what it has stood by him for through the credible rape accusation that has resurfaced – was nights like Tuesday.

Nights when he was expected to make the difference in a European affair perched on a razor’s edge.

And sure enough, he scored both in the first leg last Wednesday – when David Neres’s worldie goal equalized for a 1-1 score – and put Juve ahead in the first half of the return affair. That made it 42 career goals in the Champions League quarterfinals or later for him. Lionel Messi has the second-most, with 18 – after bagging two in Tuesday’s other knockout game, where his FC Barcelona routed Manchester United.

That doesn’t even count Ronaldo’s three goals in the last round, of course, when his hat trick overturned Atletico Madrid’s two-goal lead from the first leg to drag his team into these quarterfinals.

Before the game, Juve coach Max Allegri had professed his confidence in the outcome of the game by virtue of Ronaldo’s mere presence. “Thank God he's playing for us and not the opponents,” he said in his pre-game press conference.

But in the second half, when his side needed him most, Ronaldo went missing.

In a desperately tight game, both teams were terrified of allowing the other to get comfortable on the ball. Chances were scarce until, in the 28th minute, two Ajax defenders knocked each other over on a corner kick and Ronaldo was free to head in the go-ahead goal.

But not six minutes later, the outstanding Hakim Ziyech’s long shot was blocked by the Juve defense, only to fall kindly for Donny van de Beek, who could roll it past goalkeeper Wojciech Szczesny.

It was only Szczesny’s second-half heroics that kept Juventus in the game for as long as it was. He denied Ziyech and van de Beek somewhat miraculously. And Ajax failed to finish off several promising attacks, perhaps lacking the requisite selfishness in Juve’s box.

But then de Ligt beat three defenders on a corner to head it past Szczesny.

Ajax could have had more. But then Juve was denied what looked like a penalty when Daley Blind blocked a ball with his arm in his own box. But not even the Video Assistant Referee would give the home team a break.

Which is how the unlikeliest run in European soccer in many years continued.

Inevitably.

Leander Schaerlaeckens is a Yahoo Sports soccer columnist and a sports communication lecturer at Marist College. Follow him on Twitter @LeanderAlphabet.

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