The former Tottenham midfielder made clear his disbelief after the Gunners’ win at Brighton, shortly after City dropped more points at home with a draw against Everton, put them seven points clear.
“They’re flying high at the top of the table, can they actually win it?” he told talkSPORT.
“Now they’re seven points clear, the fact is that they can afford to lose to Man City and still win the league – that’s the scary thing!”
Mikel Arteta’s side are still not the bookmakers’ favourites to win the Premier League with the season still not at the halfway mark. They are also yet to paly defending champions City.
But O’Hara, 36, admitted his enjoyment at watching Arsenal play with his feeling that the title is now theirs to lose.
“The title is there for them now,” he continued. “They’ve got the bit between their teeth, they’ve got confidence, they’ve got that belief. Something is going on there, for sure. They’re looking a bit special.
“It’s going to be a difficult one to watch as a Spurs fan, for sure. Every time I watch Arsenal I’m like, ‘Someone just beat this team!’ It pains me to say, but I actually find it very hard not to enjoy watching this Arsenal team play.
“They’re that good.”