Chelsea boss will be feeling even better after his team's win over Southampton, but will be aware of Manchester City winning too.
Liverpool's loss to Hull was another boost for the Gunners, and in the wake of that - Chelsea rallied from a goal down against Southampton to win 3-1.
In doing so they have the Gunners lead at the top to four points, and will be hoping they can make up ground over the next month.
Manager Jose Mourinho is in no doubt just how tough it will be to win the Premier League title this year - as the league is closer than ever.
He told The Mirror: “Winning the title this year would be a greater achievement than before, yes, I think so.
“History plays a role. To win when a club is not historically a winner is a hard step to give, so 2004 was a hard step to give.
“But winning the title this season would be a really good achievement, yes.
Speaking before the Southampton game, he said: "I think the competition is different, the teams are different. In my first time it was just three teams fighting for the title."
This Chelsea side are not ready-made winners. They have not won the league since 2010, and many of the players in the squad are awaiting their first taste of Premier League success.
Mourinho is a man who has won two Champions League titles, and titles in four different countries, yet he knows a tough task when he sees one.
So fearful of the Gunners was he that he deliberately blocked Demba Ba's loan move on deadline day, worried about their chance of winning the title.
Fashioning this Chelsea side into champions, and overhauling holding off Arsenal and a resurgent Manchester City will be right up there with his very best, and that is how tough he regards the challenge ahead.
image: © Ronnie Macdonald