Ryan Gravenberch struck a stunning long-range shot on target straight after the resumption to break the deadlock and Noussair Mazraoui added a second within 120 seconds to ensure the Dutch club moved up to seven points from their four matches in the group.
David Neres added a third goal in the 66th minute with a left-footed screamer, almost struck from outside the penalty area, while Midtjylland got the late consolation penalty through Mabil.
Ajax are now only two points behind leaders Liverpool, and still just ahead on goal difference over Atalanta, who upset the English champions 2-0 at Anfield on Wednesday.
Lassina Traore missed two easy-looking chances in the first half, and struck the crossbar with a curling shot, while Zakaria Labyed was also close as Ajax failed to turn early dominance into goals.
But the 18-year-old Gravenberch enhanced his growing reputation as he thundered the ball home in the 47th minute, quickly followed by Mazraoui’s goal which came at the end of a long downfield run by the fullback, who was set up by a deft pass into his path from captain Dusan Tadic.
Brazilian Neres looked to go one better than Gravenberch with a strike from even further out, and with the left foot, to make it 3-0 to the home side at the Amsterdam Arena.
Mazraoui gave away a penalty when he tripped Australian international Mabil, who got up off the turf to convert the 80th-minute spot kick and reduce the deficit.
At Anfield, Atalanta’s two goals came in quick succession as the Serie A side revived their hopes of qualifying for the last 16.
Josip Ilicic and Robin Gosens scored goals in a five-minute span midway through the second half to gain a measure of revenge for their 5-0 thrashing by the English champions in the first match of their double-header three weeks ago.
“My only interest at the moment is that we got the thumbs-up, nobody injured, recover immediately … the boys are completely disappointed, frustrated, but really, we don’t have time for it, to be honest, just get fresh legs as quick as possible and go again,” Liverpool manager Juergen Klopp told BT Sport.
Champions League matchday 4 results
- Rennes 1 Chelsea 2
- Krasnodar 1 Sevilla 2
- Manchester United 4 Istanbul Basaksehir 1
- Dynamo Kyiv 0 Barcelona 4
- PSG 1 RB Leipzig 0
- Lazio 3 Zenit St Petersburg 1
- Borussia Dortmund 3 Club Brugge 0
- Juventus 2 Ferencvaros 1
- Olympiacos 0 Manchester City 1
- Borussia Moenchengladbach 4 Shakhtar Donetsk 0
- Marseille 0 Porto 2
- Liverpool 0 Atalanta 2
- Inter Milan 0 Real Madrid 2
- Bayern Munich 3 RB Salzburg 1
- Atletico Madrid 0 Lokomotiv Moscow 0
- Ajax 3 Midtjylland 1
Earlier, Phil Foden sent Pep Guardiola another reminder of his scoring ability by earning Manchester City a 1-0 win at Olympiacos, clinching the English team a place in the knockout stage for an eighth straight season.
The highly-rated 20-year-old forward is the rising star in City’s squad but has been unable to secure regular game time in the Premier League this season despite the team’s unfamiliar struggles in front of goal.
Guardiola gave Foden a start against the Greek champions in Piraeus and the England international responded by sweeping in the only goal of the game in the 36th minute after meeting a backheel from Raheem Sterling with a first-time shot.
In a game that often resembled an attack vs defence training drill, City failed to make their dominance count in terms of goals but barely allowed Olympiacos into the visitors’ penalty area, ultimately strolling to a victory that guarantees a top-two finish in Group C.
“Unfortunately we could only score one goal but the team is alive,” Guardiola said.
“Today we were much more incredible, much more aggressive. It’s not easy (against a defense) with nine players but our pressing was so good.”
City have won all four of their games so far in what, on paper, always looked like one of the weakest groups in terms of overall quality.
The team have never won Europe’s elite competition despite the vast spending of its Abu Dhabi ownership, and Guardiola hasn’t led a side to the title since the second of his triumphs with Barcelona in 2011.
Porto all but guaranteed they would advance with a 2-0 victory over winless Marseille.
The Portuguese club are six points and 10 goals clear of Olympiacos with two matches remaining.
In the other early match Thursday (AEDT), Borussia Moenchengladbach scored three times in a powerful first half before cruising past Shakhtar Donetsk 4-0 to stay top of Group B with two matches remaining.
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