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LONDON May 8 Middlesbrough were relegated from the Premier League after they lost 3-0 at league leaders Chelsea on Monday and will join north-east rivals Sunderland in the Championship next season.
Boro are seven points adrift of the safety zone with two games remaining and will return to the second-tier after spending just one year in the top flight.
It is the fourth time Middlesbrough have been relegated from the Premier League and captain Ben Gibson said they would have to learn lessons from this season so they could bounce back.
"It's not just tonight it's a full season," he told Sky Sports after the defeat at Stamford Bridge. "We haven't been good enough. That's every player, the staff, myself."
Boro were never really in the game after Diego Costa scored in the 23rd minute and goals from Marcos Alonso in the 34th and Nemanja Matic in the 65th wrapped up a comfortable win for Chelsea who need three points to claim the title.
"They were much better than us in every department," added Gibson. "It could have been four, five, six.... it's the lowest point of my life, not just my career. It means that much."
Boro won promotion as runners-up in the Championship last season but sacked manager Aitor Karanka in March after a dismal run which included four victories in 27 league games.
Steve Agnew took over as interim boss and they ended a 16-match winless streak against neighbours Sunderland before a draw at Manchester City but it was not enough to save them.
"I'm frustrated and disappointed. We've just come away from a silent dressing. We were well organised but we didn't get the foothold in the game," said Agnew.
"It's been a tough season. It wasn't just tonight it's been ongoing. We haven't scored enough goals."
Boro have netted 26 league goals this term - the lowest in the division - and have five wins in 36 games.
"The most important thing at the moment is the club. It's a terrific club and it's about how we reflect over the summer. We need to make sure Boro bounce back very quickly," said Agnew.
The 24-year-old Gibson added: "We have to put it right and make sure we come back stronger. The chairman Steve Gibson and those fans, they deserve Premier League football."
Chelsea manager Antonio Conte embraced Agnew at the final whistle and then went over to applaud the Boro fans.
"It's great to see a team fight with all of their strength," he said. "They went down and the supporters stayed there. This must be an example for other countries. For this reason, I felt in my heart I should go and clap the Boro support." (Writing by Ken Ferris; Editing by Hugh Lawson and Frank Pingue)