The Premier League leaders were made to work hard by a Mansfield side battling near the bottom of League One. Despite the difference in divisions, the home side produced an energetic performance and created several dangerous moments.
Arsenal eventually took the lead just before half-time through Noni Madueke. The winger had already tested goalkeeper Liam Roberts earlier in the half before finding the breakthrough. After a neat lay-off from Gabriel Martinelli on the edge of the area, Madueke curled a precise shot into the top corner.
Manager Mikel Arteta had taken a bold approach with his team selection, handing a first start to 16-year-old Marli Salmon, while another teenager, Max Dowman, became the youngest player to start an FA Cup match for the club at 16 years and 66 days.
Mansfield responded strongly after the break. Salmon was involved in the equaliser when his pass towards Cristhian Mosquera fell short, allowing substitute Will Evans to finish confidently past goalkeeper Kepa Arrizabalaga.
Sensing the danger of a cup upset, Arteta turned to his bench and introduced Eze along with defender Jurrien Timber. The change proved decisive in the 66th minute when Eze powered a strike high into the net to restore Arsenal's lead.
Mansfield continued to threaten. Arrizabalaga produced sharp saves to deny Rhys Oates and Louis Reed, while Tyler Roberts sent a curling effort narrowly wide earlier in the match.
Arsenal also had chances, with the impressive Dowman forcing two early saves from Roberts before Madueke's opener.
In the end, the Gunners held firm to secure their place in the last eight, keeping their FA Cup ambitions alive and maintaining hopes of a historic trophy haul this season.