Arsenal ended their Premier League season on a high as Olivier Giroud's hat-trick ensured they beat rivals Tottenham to second place after cruising to a 4-0 victory over relegated Aston Villa.
Spurs failed to get the point they required to make sure of second place in their game at Newcastle United, astonishingly losing 5-1.
That opened the door to Arsenal and Giroud made it six consecutive goalscoring appearances against Villa with a first-half header and two late finishes.
Substitute Mikel Arteta then forced a late own goal by cannoning a shot against the bar and in off goalkeeper Mark Bunn to ensure the Gunners kept their side of the bargain at a delighted Emirates Stadium.
Arsenal fans relished the surprise final-day turnaround as Tottenham missed out on the chance to finish above them for the first time since 1995, prior to the beginning of Arsene Wenger's reign.
While there is frustration at their failure to win the league in a season when underdogs Leicester City secured the title, it is the first time Arsenal have finished in the top two since 2005 - an achievement made all the sweeter by Spurs' late-season collapse.
Villa end the season with only three victories and 17 points to their name as they prepare for Championship football in 2016-17.
Arsenal were ahead inside five minutes when Alexis Sanchez's flick released Nacho Monreal down the left and his cross was headed home by an unopposed Giroud from 12 yards, with Bunn unable to keep it out.
Villa - who had Aly Cissokho back from suspension in their only change - briefly threatened when Jordan Ayew took advantage of poor defending from Gabriel to charge through on goal, with the hosts relieved by Laurent Koscielny's crucial clearance.
News of Newcastle's opening goal against Tottenham was greeted by a huge cheer from the home support and Sanchez came close to further improving the mood, curling an effort just wide after cruising past Jordan Lyden.
Jack Wilshere was starting his first Arsenal match since the final game of last season as part of four Wenger changes and could have marked the occasion with a goal.
The midfielder sliced off-target after Sanchez had taken advantage of Leandro Bacuna's error and picked him out at the back post, with Newcastle's second goal at St James' Park putting the Gunners in a strong position to claim the runners-up spot.
A low-key start to the second half developed into a tense atmosphere when Spurs got a goal back, before the collective cheer returned when Rafael Benitez's men restored their two-goal advantage.
Santi Cazorla collected Mesut Ozil's pass, but was thwarted by Bunn as Arsenal attempted to put their result beyond doubt.
But the win was sealed on 77 minutes as Ozil and Sanchez exchanged passes in the build-up before the Germany international squared for Giroud and the striker swept his finish into the roof of the net.
Within 114 seconds it was three, Hector Bellerin's throughball releasing the France international and he stretched to guide his low finish beyond Bunn, celebrating with Tomas Rosicky and Arteta on the sideline.
Sanchez was again denied by Bunn, but Newcastle's fourth and fifth goals ensured there was a party mood throughout the closing stages.
Arteta was given a warm welcome as he came off the bench for his last appearance at the club and then had an involvement in the fourth goal.
The experienced midfielder latched on to Sanchez's cross, seeing his shot hit the crossbar and deflect in off the back of Bunn with what proved to be the last action of the match, the veteran Spaniard reduced to tears after the final whistle.