Dan Burn opened the scoring midway through the first half with a towering header from Kieran Trippier's perfectly measured cross, before Joelinton doubled the advantage shortly after the interval, nodding home Harvey Barnes' delivery to seal a commanding result.
The win marked Newcastle's third successive triumph in Europe's elite competition, moving them up to sixth in the 36-team standings on nine points. Eddie Howe's side now sit inside the top eight automatic last-16 qualifying places on goal difference, with a six-point cushion within the knockout playoff zone.
But the celebrations were muted after Gordon was forced off in the first half clutching his hip. The 24-year-old, who recently hit a hat-trick for England, looked in visible discomfort as he was replaced by Jacob Murphy. His withdrawal dampened what had been an otherwise dominant evening for the Magpies.
After the match, Howe provided a cautious update. "I've not spoken to him yet, and I haven't had a full report from the medical team," he said. "It seems like a recurrence of his hip problem that has been troubling him for a few weeks.
"We'll assess it properly and see the extent of the damage."
Gordon originally sustained the injury during England duty in March, and it has resurfaced intermittently since. His absence could prove a major setback for Newcastle, who face Brentford on Sunday as they aim to maintain momentum in both domestic and European competition.
There was further concern when young forward William Osula was withdrawn from the bench before kick-off after feeling pain in his ankle during the warm-up. "We've been talking to him for a few days about his ankle," Howe explained. "After a discussion, we felt it was best to rest him and make sure he's fully fit before returning."
With both players facing late fitness tests ahead of the weekend, Howe will hope his side's strength in depth can carry them through another testing spell as their Champions League dream gathers pace.
Arsenal's Premier League momentum has taken a hit after star striker Viktor Gyokeres suffered a hamstring injury that will rule him out of Saturday's trip to Sunderland.
Alphonso Davies is edging ever closer to a full return for Bayern Munich following a lengthy recovery from a cruciate-ligament injury sustained in March.
Inter Milan reignited their Champions League charge on Wednesday night as Marcus Thuram made a long-awaited return from injury to inspire a tense 2-1 victory over Kairat Almaty at San Siro.
Veteran striker Robert Lewandowski continues to prove his enduring class as FC Barcelona ramps up planning for life after the Polish icon.
