They might have beaten Lille 3-0 but Ajax boss Erik ten Hag wants his players to stop attacking with such carelessness.
Al-Hilal will face Xavi's side Al Sadd in the AFC Champions League semi-finals, while Urawa Red Diamonds got past Shanghai SIPG.
Ajax began their Champions League campaign with a thumping 3-0 win over Lille on Tuesday to spark hopes of another deep run in the competition after their thrilling charge to the semi-finals last season.
Holders Liverpool began their defence of the Champions League trophy with a defeat against Napoli on Tuesday, while one missed spot-kick condemned Chelsea to defeat against Valencia and another came to Barcelona's rescue.
Portugal forward Cristiano Ronaldo said scoring his favourite-ever goal was not better than sex with girlfriend Georgina Rodriguez.
Over 300 unruly Lille fans were arrested ahead of the French club's Champions League game against Ajax for public order offences, Dutch police said on Tuesday.
Salzburg striker Erling Braut Haaland became the third-youngest player to score a Champions League hat-trick as the Austrian champions romped to a stunning 6-2 win over Genk on Tuesday.