Bruno Guimarães broke Sunderland’s resistance in the second half before Bukayo Saka converted a late penalty, giving Arsenal a 2-0 victory and preserving their perfect start to the Premier League campaign.
Footage of the incident quickly circulated online, with supporters reacting to the sight of the Argentine goalkeeper walking among them after Chelsea had suffered defeat.
Arsenal showed the resilience of champions as they recovered from an early Chelsea shock to secure a 2-1 victory in a pulsating London derby at the Emirates Stadium.
The Belgium winger was initially on Arsenal's radar, but the Gunners decided against paying Lyon's asking price of around £30 million. That decision opened the door for Sunderland, who moved quickly to agree a deal and put themselves in pole position for the 21-year-old.
Arsenal had to work for the victory, with both teams struggling to create clear opportunities during a cagey opening half. Villa came closest to breaking the deadlock when Emiliano Buendia's long-range effort struck the crossbar, while Arsenal's Gabriel Magalhaes and Saka also had attempts but failed to seriously trouble the home side's goalkeeper.
The draw was conducted under the Champions League's expanded format, with each of the 36 teams set to play eight different opponents — four at home and four away.
The exact dates and kick-off times for the individual matches will be announced by UEFA on Saturday, August 29.
Negotiations have moved quickly over the past 24 hours, with the two clubs now close to reaching an agreement for the Brazil international.
The final decision, however, will belong to Martinelli.
Arsenal supporters were left impressed by Christos Tzolis after the Greek winger produced an eye-catching performance in his Premier League debut against newly promoted Coventry, contributing an assist in the Gunners' victory.
The 24-year-old, who joined Arsenal from...