The French striker’s 29th-minute glancing header from Tuncay Sanli’s powerful cross cancelled out Emanuel Adebayor’s opening goal for the Gunners 12 minutes earlier.
Shortly after Aliadiere’s equaliser, Middlesbrough had a penalty appeal dismissed when winger Adam Johnson was tripped by Arsenal defender Gael Clichy.
Arsenal manager Arsene Wenger had brought back his key players after resting them for the midweek Champions League loss at FC Porto, and two of them combined in the 17th at the Riverside.
From a corner, captain Cesc Fabregas picked out the unmarked Adebayor to head down into the net from six metres.
Abou Diaby, who had a shot blocked by goalkeeper Ross Turnbull’s legs before the opening goal, was denied again before the home side struck back.
Clichy’s clearance down the left flank was blocked, enabling Tuncay to pick up possession and whip in the cross for Aliadiere to score.
Boro pressed for a winner and on the hour, Julio Arca released Stewart Downing, who darted into the area only to see his powerful strike turned away by goalkeeper Manuel Almunia.
At the other end, Arsenal’s Robin van Persie picked up Diaby’s pass, but scuffed the shot wide across the face of goal. Turnbull denied Arsenal striker Nicklas Bendtner a chance to claim the glory when he parried the substitute’s shot with four minutes left.—AP