Middlesbrough interim head coach Steve Agnew admitted he walked into a silent dressing room after their relegation was confirmed at Chelsea.
Boro barely threatened and the defeat makes it a swift return to the Sky Bet Championship, one year and one day since they earned promotion against Brighton.
"It's very, very frustrating - it's a very silent dressing room in there," Agnew told Sky Sports.
"Chelsea just had too much for us tonight. We were reasonably well organised but we didn't get a foothold in the game for long enough in order to create chances.
"We conceded two goals which we were unhappy with from a defensive point of view - it gave us a mountain to climb. Chelsea have got a high degree of technical ability and they play the game at top speed - you have to stay with them, and we didn't do that."
Middlesbrough have won just five Premier League games this season - the joint fewest in all four English divisions, with Sunderland and Rotherham.
Aitor Karanka was sacked in March but results haven't improved under Agnew, who wasn't willing to discuss his future when asked.
"It's been a really tough season - it's been ongoing since the season started," he said.
"It's a really disappointing evening. We haven't scored enough goals - you've got to score goals to win football matches.
"The most important thing at this time is the football club - it's a magnificent club. It's not about my situation.
"We'll try and finish the season strong and then reflect over the summer. We've got to try and bounce back as quickly as possible."