Declan Rice thumped home a stunning second-half winner as Arsenal secured second spot in the Premier League table and a return to the UEFA Champions League for a third straight season.
After Arsenal goalkeeper David Raya made several key stops in the first half, Mikel Arteta's men upped the pace after half-time with Rice slamming a thumping drive from 22 yards on 55 minutes beyond the helpless Newcastle goalkeeper Nick Pope as he dived to his right.
It means Arsenal's trip to Southampton on the final day is effectively a dead rubber with The Gunners five points clear of Newcastle, Chelsea and Aston Villa in the top-five chase.
Eddie Howe's Newcastle were chasing a historic fourth win over Arsenal this season, but must now defeat Everton at St James' Park next week to join the London side in the Champions League next term.