The 28-year-old had been out of action for the Gunners for nearly a year after rupturing her ACL in November.
She has proved key for Arsenal since she signed from Sunderland in 2017 and her presence was sorely missed last season.
Mead was named as a substitute in their Women's Super League clash with Aston Villa on Sunday and proved her class off the bench.
Mayumi Pacheco gave the visitors the lead at the Emirates Stadium in the 25th minute, a fine header from Lucy Staniforth's corner.
As the clock ticked down, it looked as though Arsenal were set to go winless for a third straight league game.
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However, Katie McCabe kickstarted their comeback in the second minute of second half stoppage time with a powerful strike into the roof of the net.
Just moments later, 88th-minute substitute Mead teed up Russo on the edge of the area and saw her shot creep in for the winner.
There's no surprise she turned provider considering she holds the record for the most assists in WSL history.
Sunday's assist was her 43rd in the league and it proved crucial as Arsenal picked up their first win of the season.
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The Gunners fell to a 1-0 defeat on the opening weekend against Liverpool before drawing 2-2 with Manchester United Women.
They also crashed out of the Champions League in the qualifying rounds, losing on pentlaties to Paris FC Feminines.
However, the latest result could signal the start of a run of form as they eye another top three finish in the WSL.
And with Mead back in the frame, Jonas Eidevall's side could be set to challenge at the top once again.