Dan Burn’s and Alexander Isak’s goals either side of halftime threw the Toon Army into a frenzy, setting them up for a victory that will make manager Eddie Howe and his team famous on Tyneside.
Isak jumped to finish clinically from Jacob Murphy’s knockdown after 52 minutes, but Burn celebrated his maiden England call-up by meeting Kieran Trippier’s corner with a thunderous header in first-half stoppage time.
Federico Chiesa, a replacement, gave Liverpool a goal in injury time after the team was eliminated from the Champions League on penalties by Paris St-Germain in the middle of the week.
Nevertheless, Newcastle overcame a close finish to win their first domestic championship and major trophy since the Inter-Cities Cup in 1969.