Emirates Stadium, London (CNN)As goodbyes go it wasn't supposed to be quite like this.
Ten-man Atletico Madrid battled to a 1-1 draw against Arsenal in the first leg of their Europa League semifinal on Arsene Wenger's final European night in north London.
Everything seemed to be going to Wenger's script with eight minutes to go -- "1-0 to the Arsenal," as their famous chant goes -- but a late equalizer from Atletico forward Antoine Griezmann canceled out Alexandre Lacazette's earlier headed effort, leaving the tie in the balance for the second leg.
It was a heated affair from the kickoff, with Atletico defender Sime Vrsaljko sent off in the ninth minute, shortly followed by his manager Diego Simeone -- sent to the stands for dissent.
The Europa League remains Wenger's final chance to claim a trophy with Arsenal, and would be his first European silverware in his 21-year reign at the club, having lost the 2006 Champions League final to Barcelona.