Leicester came within inches of retaking the lead as Leno charged off his line but got nowhere near James Maddison's corner, which Ndini thundered against the crossbar. Indeed, Lacazette released Ozil inside the Leicester box with a fine pass, and the German's flick was turned home by Aubameyang for his second of the match.
And Mustafi says Ozil's goal before half-time was key to their win.More news: Navy Sails 2 Ships Through Taiwan Strait in Defiance of China
Meanwhile, Emery has also sprung a surprise by naming Aaron Ramsey and Pierre-Emerick Aubameyang on the bench again despite their strong showings against Fulham.
The victory was Arsenal's 10th on the bounce, a fitting number for the star of the show, the Gunners No 10, Mesut Ozil.
"When you give him the opportunities in his favourite position behind the striker, he has the capability of doing everything - making goals and scoring".More news: 1,000+ tips pour in to find missing 13-year-old Jayme Closs
Arsenal could welcome back Mesut Ozil for the Premier League visit of Leicester on Monday night. "He can make us look very unsafe going forward".
Unai Emery's Gunners have won their last nine games in all competitions, including six straight in league play.
Arsenal edged to a thrilling 4-3 win over Leicester at The Emirates in the opening Premier League fixture of the 2017-18 season after Alexandre Lacazette scored on his home debut.More news: Ariana Grande hide her "Pete" tattoo with band-aid
The Gunners have moved to within two points of Chelsea, Manchester City and Liverpool at the top of the table after their recent run as they continue to thrive under Unai Emery.