Sheffield United denied Arsenal the opportunity to go third in the Premier League table on Monday night when they took all three points at Bramall Lane.
The game finished 1-0 to the hosts with Lys Mousset scoring the goal from close range near the half-hour mark. It was the Frenchman's first start for the club.
Arsenal's record signing Nicholas Pepe missed a golden opportunity from close range just a few minutes prior to the Blades' goal.
Despite missing out on the qualifiers, the Republic of Ireland International David McGoldrick started and played 78 minutes. Compatriots Enda Stevens and John Egan both played the full 90 minutes at Bramall Lane.
Granit Xhaka forced Dean Henderson into action in the with a long-range effort, but the Blades closed the game out for a famous win.
The result, the biggest since their promotion back to the Premier League moved the Sheffield club up to ninth. They are now four points clear of the relegation zone.
Defeat for Arsenal, their first since August, means they missed the chance to move back into the top four. The Gunners sit fifth in the table, two points behind Chelsea in fourth.
After the game, Sheffield United boss Chris Wilder praised the opposition but was clear that his side is not in the Premier League to make up the numbers.
"We're not here to make the numbers up. We're playing against unbelievable teams and unbelievable players and fabulous football clubs but we think we're alright." Wilder continued, "We're a decent little club that's battling it out."
"We needed to produce a big performance because we're playing a team that's a historic football club. A team that's expected to go really well this year, top four and higher. This is a big result for us.
Arsenal boss Unai Emery was keen to focus on how his side was evolving and looking for more consistent performances.
"We have challenges in each match. Tonight was a very big challenge to get three points and also be consistent and continue improving things, doing things our way. Playing with young players and getting experience."