With the Celtic Park grass still bedding in, new signing Saidy Janko watched his team-mates in action for the first time at St Mirren Park in Paisley.
Another summer signing, Dedryck Boyata, cruised through his first appearance in the green and white hoops alongside Virgil van Dijk in central defence.
Celtic boss Ronny Deila did not include any of the nine players who were given an extra week off because of their international duties in June.
That meant starts for academy players, left-back Kieran Tierney and midfielder Luke Donnelly, along with the likes of Tom Rogic and Stefan Scepovic, but Derk Boerrigter began on the bench.
Mackay-Steven took less than three minutes to net after latching on to Stuart Armstrong’s through-ball and rounding the goalkeeper, and Celtic kept the pressure on the Dutch side.
Mackay-Steven (25) danced his way past several players before his shot hit the Dutch goalkeeper and went in off defender Kadeem Pantophlet.
The former Dundee United winger was felled by a wild tackle which earned Jordy Winden a yellow card but soon set up Donnelly, whose shot was cleared off the line.
Scepovic, Tierney, Henderson, Armstrong and Rogic all had efforts saved and Lustig headed against the bar in the first half but the second half proved to be a non-event as Celtic fielded mostly youth team players.
Elsewhere, trialists Jordan Roberts and JJ Hooper both scored for Inverness for the second friendly in a row as the William Hill Scottish Cup holders won 3-0 at Brora Rangers.
Former Aldershot winger Roberts slotted home in the first half following Aaron Doran’s pass and former Newcastle youth striker Hooper netted from a tight angle after the break. Doran added a late third.
Swiss-born Albanian Mergim Bajraktari played 45 minutes for Hearts in their 2-0 win against Bohemians in Dublin. The midfielder most recently played for Stade Nyonnais in Switzerland.
New Spanish forward Juanma Delgado headed against the bar for Hearts, who played entirely different teams in each half, before Callum Paterson’s cross deceived the home goalkeeper with three minutes left. Soufian El Hassnaoui scored from the spot two minutes later.