Mikel Arteta’s men are edging towards a first league title in 22 years as their advantage over City, who have a game in hand, now stands at nine points.
The Gunners struggled to break down a dogged Everton defence for 89 minutes until Dowman’s cross fell to Viktor Gyokeres to open the scoring.
The teenager then ran from deep inside his own half to roll into an empty net after Everton goalkeeper Jordan Pickford ventured forward for a corner in stoppage time.
Meanwhile, City’s season is in danger of coming off the rails as West Ham clung on for a point that lifted them out of the relegation zone for the first time in three months.
Pep Guardiola’s men were thrashed 3-0 by Real Madrid in the first leg of their Champions League last-16 tie in midweek and have dropped four points to sides battling relegation in their last two Premier League outings.
Bernardo Silva’s attempted cross floated in at the far post to give City the lead at the London Stadium.
But the advantage lasted less than four minutes before Konstantinos Mavropanos headed in from a corner.
City dominated the second half but failed to find a way through as Erling Haaland’s barren spell in front of goal goes on.
Also on Saturday, fifth-placed Chelsea were beaten by Newcastle at Stamford Bridge to round off a painful week.
Thrashed 5-2 at Paris Saint-Germain in the last-16 first leg, Liam Rosenior’s side were breached in the 18th minute when Anthony Gordon converted from Joe Willock’s pass.
Chelsea will drop to sixth as long as Liverpool avoid defeat against struggling Tottenham on Sunday, with the top five set to qualify for next season’s Champions League.
A rare win at Stamford Bridge propels Newcastle up to ninth and within six points of the top five. (AFP)
Edited by Tony Sabine
