Arsenal climbed above Everton into ninth place and sit four points behind fifth-placed Manchester United.
Mikel Arteta turned to youth at Dean Court and Bukayo Saka, Eddie Nketiah and Joe Willock repaid the Arsenal manager's faith with influential displays.
Arsenal made Leeds pay for their profligacy with a host of wasted first-half chances before Reiss Nelson scored the winner 10 minutes into the second period.
Mikel Arteta got everything he asked for in his first win as Arsenal manager with a rampant first 45 minutes from the Gunners earning a 2-0 victory over Manchester United.
Mikel Arteta was hired by Arsenal on Friday after agreeing a three-and-a-half-year contract to replace the sacked Unai Emery.
Mikel Arteta signed a three-and-a-half year contract and ends a three-year stay as Pep Guardiola's assistant at Manchester City.
Jamie Vardy scored in 10th consecutive Premier League game as Leicester has only lost one league game this season under new coach Claudio Ranieri, who took over in the summer after the team won seven of its last nine games last season to survive.
Mikel Arteta, who was at risk of leaving the London side as his deal expired this summer, made only 11 starts across all competitions last season due to injury problems.
Arsenal captain and midfielder Mikel Arteta will be out of action for three months, while full-back Mathieu Debuchy has suffered a dislocated shoulder.
Arsenal manager Arsene Wenger expects Ozil and Arteta to return to action in January, while Theo Walcott, Aaron Ramsey and Laurent Koscielny are due back imminently to help reignite the Gunners' quest for a top-four finish in the Premier League.
Arsenal need a draw against Group D leaders Dortmund at the Emirates Stadium to be sure of joining the German club in the knockout stages of the Champions League.
The past 10 years have seen Arsene Wenger's team achieve a top-four finish on every occasion, but not once have they been strong enough to pip either Chelsea, Manchester United or Manchester City for pole position on the final day.
The weekend victory at Cardiff City maintained Arsenal's four-point lead at the top of the Premier League table and they will attempt to consolidate their position when Hull City visit the Emirates Stadium on Wednesday.
Oxlade-Chamberlain is one of several players who picked up injuries in Saturday's 3-1 home defeat to Aston Villa, leaving manager Arsene Wenger with a selection headache for Wednesday's crucial Champions League qualifier against Fenerbache.
French forward Olivier Giroud scored a first-half hat trick, as Arsenal pummeled the Vietnamese national team into submission with a 7-1 romp.
Bayern Munich join Bundesliga rivals Borussia Dortmund in the last eight draw on Friday while Arsenal must fight to finish in the top four of the Premier League, or otherwise yet another trophy-less season will not even have the consolation of a Champions League place for next term.