Iwobi became the first Nigerian player to score in an European club competition, including the European Cup, UEFA Champions League, UEFA Cup, UEFA Europa League and UEFA Cup Winners’ Cup.
The Gunners missed the chance to qualify for next season’s Champions League after they were thrashed by Chelsea.
Super Eagles star Alex Iwobi came off the bench in the 66th minute.
Giroud, a former Arsenal player, gave Chelsea the lead with a header three minutes into the second half before goals from Pedro RodrÃguez and Eden Hazard in the 60th and 65th minute respectively gave Chelsea their deserved win.
Three minutes after his introduction, the 23-year-old Super Eagles Iwobi lashed in a tremendous volley from outside the area to make it 3-1 to give Arsenal a flicker of hope.