Antonio Conte admitted Chelsea's shock 2-1 defeat against Crystal Palace has blown the Premier League title race wide open.
Conte's side went into Saturday's clash with relegation-threatened Palace sitting 10 points clear at the top of the table and having won their previous 13 fixtures at Stamford Bridge.
But after goals from Wilfried Zaha and Christian Benteke fired Palace's stunning upset and second-placed Tottenham won at Burnley, Chelsea found their lead cut to seven points with nine games remaining.
And Blues boss Conte conceded the battle is back on, with his players needing to bounce back when Manchester City visit Stamford Bridge in midweek.
"For others this is a good result. It makes it more interesting, the championship," Conte said.
"But I always said that the league finishes when it is mathematically sure you have won. Otherwise you must play every game to try to win because, I repeat, in England easy games do not exist.
"We have to play on Wednesday against Manchester City and we all know the strength of this team.
"But, now, the most important thing is to recover very well and rest.
"It's important to prepare in the right way for this game, but I think, in England, there are no easy games.
"You could see that today against Crystal Palace. Every game will be very tough from now until the end.
"Also, if the team is Manchester City or a side fighting in the relegation zone."
Cesc Fabregas had put Chelsea ahead after five minutes, but Zaha equalised four minutes later and Benteke gave Palace a lead they would hold onto in the 11th minute.
Ivory Coast winger Zaha was the game's outstanding player and Palace manager Sam Allardyce believes the player is now delivering on his undoubted potential.
- Outstanding -
"Wilf must feel really good about himself. It's about consistent performances at the moment," he said.
"It was there before he left for the Ivory Coast. He's continued to show that with them, and he showed it today with his performance and quality of football in possession.
"There's a man on the other side, an outstanding individual like Wilf in Eden Hazard. His ability is something Wilf could look at to try and match.
"Him and Christian were our match winners, and protecting our lead was our goalkeeper and the defence.
"Wilf is already realising his potential with the way he's playing. Potential is becoming a reality."
Palace remain just four points clear of the bottom three, but Allardyce believes his players are growing in confidence.
And he singled out France centre-back Mamadou Sakho for praise, although any talk of securing a permanent move for the on-loan Liverpool defender will have to wait until the club's relegation battle has been concluded.
"Securing our Premier League status is our priority, and then we'll see what Mamadou Sakho's aspirations are, to be with us or anywhere else," he said.
"His future doesn't look as if it is at Liverpool. He's enjoying his football and his life here.
"He's brought that resilience to the team by leading by example. He's taking a commanding role in his performance and the information he's giving out on the field.
"That has helped with our defensive resilience: one goal conceded in four games."
The only setback for Allardyce was the loss of defenders James Tomkins and Scott Dann to injury.
"Scott has injured his knee. Joel Ward fell on his knee and he felt something go in his knee," Allardyce said.
"Losing James and then Scott is a blow for us. But Martin Kelly and Damien Delaney came on and never put a foot wrong."