Suddenly, we have a title race.Chelsea were unable to respond to Tottenham Hotspur’s win over Bournemouth on Saturday, falling 2-0 to Manchester United at Old Trafford.Goals from Marcus Rashford and Ander Herrera handed Jose Mourinho’s side a well-earned win but, perhaps more importantly in the grand scheme of things, ensured Chelsea’s lead over Spurs remains just four points.Antonio Conte’s side have now lost two of their past four games and the Italian should be rather concerned after today’s performance.The Blues were second best in all areas. Ander Herrera kept Eden Hazard quiet, Paul Pogba won the middle battle against N’Golo Kante and David Luiz will have nightmares of Marcus Rashford tonight.And this was an understrength United side, too. Zlatan Ibrahimovic and Henrikh Mkhitaryan were both on the bench and Anthony Martial couldn’t even make the Red Devils’ squad.But with Rashford producing a truly stunning performance, United were always going to stand a chance.“Brilliant display from a 19 year old with a wonderful future,” Gary Lineker tweeted. “Marcus Rashford is special.”

The teenager opened the scoring when he latched onto Herrera’s pass and fired past Asmir Begovic.

It was a lead United wouldn’t relinquish. In the 49th minute, Herrera doubled the score when his shot deflected off Kurt Zouma and flew beyond the Chelsea goalkeeper.

Herrera was excellent

For the Spaniard to be involved in both goals is mightily impressive considering his one task was to man mark Hazard.

Cahill's questionable moment

For a clear sign of just how much Chelsea were off the pace today, you need to see what Gary Cahill did before Herrera’s goal.

Ashley Young delivered a cross that was cleared by Luiz. As he attempted to get on the end of Young’s cross, Jesse Lingard was accidentally knocked over.

The ball was still in play - Young retrieved the ball after Luiz’s clearance - when Cahill spotted that Lingard was on the floor.

Apparently unaware that Young was threatening again, the Chelsea captain went to help Lingard back to his feet.

Video: Cahill helps Lingard to his feet

Great sportsmanship yes, but clever? Absolutely not. Check it out below.

It’s pretty unforgivable behaviour really. Chelsea are fighting for a Premier League title and their captain is missing his defensive duties to help an opponent back up.

Fans react

Nobody could believe what Cahill did.

Will Chelsea win the Premier League? Let us know in the comments section below!