With a 2-1 final-weekend victory over Leicester City at Highbury, Arsenal became the first side since Preston in 1888/89 to go through an entire league campaign unbeaten.
Having already won their third Premier League title, the Gunners went into their last match knowing that by avoiding defeat, they would write their names in footballing history.
Leicester, who had been relegated two weeks earlier, threatened to put a halt to the party when Paul Dickov put them in the lead.
But Thierry Henry and Patrick Vieira replied for Arsenal to seal a memorable victory.
The Gunners ended up with 26 wins and 12 draws and finished 11 points clear of second-placed Chelsea.
West Bromwich Albion became the first Premier League team to avoid relegation having been bottom at Christmas as they claimed a 2-0 win over Portsmouth on the final day of the season.
The Baggies started the final day in last place but goals from Geoff Horsfield and Kieran Richardson meant they were the only team in the bottom four places to win.
And when fans and players heard that Crystal Palace had drawn 2-2 at Charlton, courtesy of Jonathan Fortune's late equaliser, the celebrations could start in earnest at The Hawthorns.
West Brom finished in 17th, one place and five points behind Portsmouth, with Palace, Norwich City and Southampton going down.