Manager Danny Wilson admitted a lack of a ruthless streak had cost Barnsley their place in the Sky Bet Championship as they were relegated following a 3-1 defeat at Middlesbrough.
Barnsley went ahead early in the second half through Jean Yves Mvoto to raise hopes they could pull off an escape, but Lee Tomlin levelled within 60 seconds before goals at the death from Danny Graham and Tomlin finally condemned the Tykes after a long season of struggle.
Demotion to the third tier came 17 years to the day after Barnsley had been promoted to the Premier League.
"It's hard to explain how I feel right now, but I feel empty," said Wilson. "It's a difficult feeling to put into words how we feel right now.
"We are down and we are disappointed but we prolonged it for longer than people expected it. With another three or four games who knows? It's all hypothetical.
"It was a brave effort but this game summed up our season. We've not scored enough goals.
"We get a goal ahead but don't seem to be able to get it over the line. We've not got enough fire-power in the team. We're not going to score three and four and that's been the problem.
"There have been times we've been a goal ahead and not held on, and that's a mentality we have to change. It's not just the strikers, it's the whole squad. We need to get some goals in the squad.
"We can mope around if we want or we can start looking forward and planning to next season."
Boro boss Aitor Karanka was delighted to finish with a win in the final fixture at the Riverside and admitted he was already thinking about next term.
"I said to the players that this was a very important game," he said. "I told them it was not the last game of this season, it was the first game of next season.
"They have to work now for the future. We did well today but we can always improve and get better."
However, Karanka also felt it was not the most polished performance as Boro squandered a string of chances and only sparked into life after Barnsley got the opener.
"It was not brilliant but we won and that was what counts," he said.
"My players only woke up after Barnsley had scored. For the first 25 minutes I was disappointed because we had started so slowly, but after that we played with more intensity and created chances.
"If you do that the goals will come and for that I am happy."