Ajax Amsterdam s Ivorian forward S bastien Haller reacts during the UEFA Champions League Group C football match between Ajax Amsterdam and Besiktas at The Johan Cruijff ArenA in Amsterdam on September 28, 2021. AFP
Four-time European champion Ajax now has scored seven goals in its two Champions League matches this season after routing Sporting Lisbon 5-1 two weeks ago in the Portuguese capital.
Steven Berghuis put Ajax ahead in the 17th minute, sweeping a left-footed shot low into the corner of the net after Dusan Tadic dribbled through the Besiktas defense.
Berghuis turned provider for Haller in the 43rd minute, crossing from the right for the Ivory Coast forward to deflect the ball into the net off his thigh.
Haller is the first player to score five times in his first two Champions League matches.
Ajax, which has scored 30 goals in seven Dutch league matches this season, could have won by more against a team missing key players through injury and illness but for some poor finishing and good saves by Besiktas goalkeeper Ersin Destanoglu, who twice denied Haller and blocked a shot by substitute David Neres in the 85th.
Ajax eased up in the second half, giving Besiktas a chance to get back into the match. Kenan Karaman looked to have scored in the 62nd minute but his effort was ruled out by referee Benoit Bastien for a foul on Jurrien Timber.
Borussia Dortmund, which beat Besiktas 2-1 two weeks ago, was hosting Lisbon later Tuesday.