Georginio Wijnaldum gave the hosts the lead late in the first half, and a quick double from Philippe Coutinho and Adam Lallana after the break set off the celebrations at Anfield.
The Reds needed to win to stay ahead of Arsenal in the Premier League standings, with the Gunners now relegated to next year's UEFA Europa League.
Off The Ball shared the team sheet for Sunday's match:
Liverpool were desperate for a win and came out with plenty of intensity on Sunday. After just six minutes, Nathaniel Clyne pulled a shot wide following a promising attack.
Anfield was fully behind the team, but doubt crept in early, as news came in from the other venues that both Arsenal and Manchester City―their rivals for the Champions League spots―had taken the lead. Goal summed the fans' reaction up like this:
And Boro put up quite the fight in the first half. Minutes after Emre Can fired wide, Patrick Bamford was dragged down by Dejan Lovren in the penalty pox. The official could―and perhaps should―have given a penalty and a red card, per the Associated Press' Steve Douglas:
Instead, the Reds were able to fight on at full strength. Daniel Sturridge went close after 32 minutes, with Brad Guzan reduced to a spectator as the ball went wide, and Stewart Downing almost forced a crucial mistake from Joel Matip.
Wijnaldum finally broke the deadlock in added time of the first half, as Roberto Firmino beautifully islolated the Dutchman, who finished easily.
ESPN FC's Iain Macintosh warned against complacency:
The Reds needed a second goal to be sure of the win and found it early in the second half, as Coutinho cleverly anticipated Brad Guzan's step to the side and curled his free-kick the other way.
Dominic Shaw of Gazette Boro didn't think the stopper was all that convincing during the sequence:
The goal seemed to liberate the Reds, who added a third shortly after, with Wijnaldum setting up Lallana. Joe.co.uk couldn't help themselves:
Chances now came at a rapid pace, as everyone wanted to join the party. Firmino should have shot himself instead of trying to play in Wijnaldum, allowing the defence to return, and Guzan redeemed himself with a solid save to deny Coutinho.
Wijnaldum fluffed a spectacular volley completely, but Anfield didn't seem to mind, as the home fans were too busy celebrating.
Simon Mignolet made a spectacular save after a Calum Chambers cross turned into a shot, sacrificing his own health to keep the ball out.
Manager Jurgen Klopp gave a number of players some minutes late, with Lucas Leiva enjoying every second of his short spell as a substitute. All that was left was the final whistle, sending Anfield into a delirium.