Manchester City's Premier League title challenge was boosted by a 3-0 win at Manchester United in midweek, while the Gunners have had their championship hopes dented badly by two disappointing results.
Third-place City (21-3-5) closed the gap on leaders Chelsea to only three points with an emphatic victory in the Manchester derby on Tuesday and still have two games in hand on both the Londoners and Liverpool, who are in second place - one point above the Citizens.
City boss Manuel Pellegrini was delighted with his side's display against United, which featured two goals by striker Edin Dzeko and a third from skipper Yaya Toure.
"I think that we really did a very good performance in all senses," Pellegrini told his club's official website. "It was important psychologically because it's one of the three matches we had postponed against a great team like United.
"We must play the other two at home - if we keep recovering points against Liverpool and Chelsea - we are now four points up on Arsenal, so it's very important to keep adding points. We have to play nine games more, you cannot know how many points you need to win. It's important to keep playing the way we did today."
City have won four straight league matches and kept clean sheets in the last five. Pellegrini's side have gone 418 minutes without conceding a league goal since Branislav Ivanovic scored in Chelsea's 1-0 win at the Etihad in early February.
Arsenal (19-6-6) have slipped down to fourth place after crashing to a heavy 6-0 defeat at Chelsea last weekend and then dropping two points in a 2-2 home draw against Swansea City on Tuesday.
The Gunners fought back from a goal down to lead the Swans 2-1 only for Mathieu Flamini to score an unlucky 90th-minute own goal to rob Arsene Wenger's side of a much-needed victory.
French midfielder Flamini insists Arsenal must bounce back against the Citizens.
"That's going to be a big one," Flamini told his club's official website. "We want to do well, especially after the big loss against Chelsea. We want to prove that we're one of the big teams in the Premier League.
"Of course it's very disappointing because it was a difficult game. We conceded an early goal, we didn't play a great first half but we were trying, trying, trying. We wanted to come back for the fans, especially because they have been behind us since the beginning of the season and especially after the 6-0 defeat against Chelsea. We wanted to react to give them a positive game but unfortunately we conceded at the end."
The Gunners have gone 14 home league matches without defeat since losing 3-1 against Aston Villa at the Emirates on opening day.
Arsenal are still without Mesut Ozil (hamstring), Aaron Ramsey (tendon), Jack Wilshere (broken foot) and Theo Walcott (knee), while City have injury concerns over Sergio Aguero (hamstring) and Matija Nastasic (knee).
Man City beat Arsenal 6-3 at the Etihad Stadium in December. Fernandinho scored twice while Alvaro Negredo, David Silva, Aguero and Toure also tallied. Walcott scored twice for the Gunners while Per Mertesacker added another in stoppage time.
The Gunners have won only two of their last 11 matches against City in all competitions dating back to April 2009.