Manchester United goalkeeper David de Gea believes the acquisition of Mesut Özil in the summer transfer window has been the decisive factor in propelling Arsenal to the summit of the Premier League table.
The signing of Özil was viewed as something of a coup for the Gunners, despite the club record £42.5 million paid to Real Madrid to sign the German, and his arrival provided a much-needed fillip after a summer of inactivity in the transfer market.
Özil has scored twice and provided four assists in his eight Premier League appearances, and his influence has proved vital in maintaining Arsenal's place at the top of the table into late November.
Arsenal retain a two-point advantage over nearest rivals Liverpool, while Manchester United are five points behind the leaders, and De Gea has been impressed by what he has seen from the Emirates Stadium club so far this term.
"They've been very good - there's no denying that," he told the official Manchester United website.
"I think Mesut Özil has made a big difference to them. Everybody can see what a good player he is.
"It's still early, though, and there's a long way to go in the season. Obviously Arsenal started well but there are many games still."
Arsenal's last outing in the league was their encounter with Manchester United, which the Old Trafford club won 1-0 to condemn Arsene Wenger's side to their only defeat since the season's opening day.
The Gunners will, however, have the opportunity to reestablish an eight-point advantage over the champions given that they meet Southampton on Saturday, 24 hours before United face Cardiff.