As a former centre-half himself, Bruce would have been disappointed to have seen skipper Lascelles drawn towards the ball which left Aubameyang free to score the decider.
Up until then his backline coped admirably with the pace of the Gunners - producing the type of disciplined display seen on countless occasions under the stewardship of predecessor Rafael Benitez.
At the other end Brazilian Joelinton had a lively debut, and roused the home crowd when he slalomed past two challenges to hammer in a low shot saved by Leno.
And Shelvey, who will be hoping to once again become a regular fixture in the Newcastle midfield, showed his prowess from distance with a vicious drive which shook the rain off the woodwork.
Joelinton and Miguel Almiron both worked tirelessly, but did not quite click up front as they partnered each other for the first time in a competitive fixture.
But it is worth noting that Ayoze Perez and Salomon Rondon took until the second half of last season to form a potent union, which eventually reaped 23 goals.
There was enough shown on the pitch on Sunday to suggest that there are better days to come for Joelinton and Almiron.
◾Newcastle haven't won their opening game in any of their last six Premier League campaigns.
◾Newcastle manager Bruce suffered defeat in his first game at a new club for the first time since December 2001, when he began his Birmingham City reign with a 2-1 defeat to Wolves in the second tier.
Newcastle are at newly-promoted Norwich City on Saturday (15:00 BST).