Reading manager Jose Gomes labelled his side's poor start to their 4-1 Sky Bet Championship defeat at home to Swansea as "unacceptable".
The Royals were defensively woeful in the first half, allowing Swansea to take a 3-0 lead at the break.
Oli McBurnie – after just two minutes – Connor Roberts and Mike van der Hoorn were on target.
McBurnie added a penalty three minutes after the interval – his 10th goal of the season – to give Swansea total control.
Although Callum Harriott pulled a goal back, Reading are now winless in 10 matches – the past three with Portuguese Gomes in charge.
"I'm a bit disappointed by the way we started this game," Gomes said. "We are at the bottom of the table. We have no time, no space, no chance at all to start games like this.
"We must start games with all our strength, all our energy. Today, I didn't like it. We must play football. It is not a war, it is a football game.
"I promise you that of all the games I have been in charge here, we cannot see this anymore.
"It is unacceptable the way that we start. We must give everything, we cannot save energy. They cannot hide anything from me.
"I was angry with the players afterwards, of course. They said things as well, of course, but that stays inside the changing room.
"Today definitely shows how big my job here will be. It is a tough mission but we can get there. We will get there."
Swansea ended a run of three games without a win to revive their play-off hopes.
"It was a really good win," manager Graham Potter said. "I was really pleased for the players and our supporters.
"I was very proud of our performance and, of course, delighted with the result.
"It helps to score early on because goals change the games. It was good to be 4-0 ahead because it doesn't happen too often.
"You sort of enjoy it but you don't enjoy it because I respect this league and it doesn't take much for the ball to be in the back of your net. We've been punished quite heavily over the past few games.
"I thought we played really well over the first 20 minutes today and it really helps when you're ahead in the game.
"Reading had a bit of a good spell then, which we saw out and then scored again. And the goals changed the complexion of the game.
"What we wanted to – attacking and defending – we did. It was our day today. We were good and well worthy of the victory and I'm happy for the players and supporters."
