Chris Iwelumo and Chris Eagles both grabbed a brace in a match that will be particularly pleasing for the Clarets boss Brian Laws, whose name appeared in a few Tigers chants when he was in charge of Scunthorpe.
Pearson had thought Hull had put their early season wobble behind them with three straight clean shears, and had no answers as to why they were so bad at Turf Moor.
"Where do you want to start? They didn't have to work hard enough for their goals, we didn't stop crosses, didn't track runners," he said.
"It was a shocking performance and we'd kept three clean sheets prior to that and looked harder to beat. I'm not happy about the performance but it's my team and my responsibility."
Neil Warnock, the Queens Park Rangers manager, has told talismanic midfielder Adel Taraabt to get used to being man-marked.
He has been the creative spark for table-topping Rangers since joining from Tottenham Hotspur in the summer, and was the man Millwall knew they had to keep quiet when they visited Loftus Road on Tuesday night.
They kept him out of the game and were rewarded with a point from a goalless draw.
"They man-marked Adel, and we know that a lot of teams will do that now. So what we did was play him as a striker, making his marker play as a centre-back - I thought Adel did quite well," said Warnock.
"You've got to give Millwall credit. They defended for their lives. Kenny Jackett gets the maximum out of his team and they needed to be at their maximum, because I thought we were very good."
Steve Cotterill, the Portsmouth manager, conceded he has had been forced to mislead the media after taking charge at Fratton Park in the summer.
Pompey climbed out of the relegation zone on Tuesday night thanks to a 3-1 win over Bristol City.
"What I had to do this season was come in and feed you guys a lot of bull - tell you everything, but tell you nothing," said Cotterill, referring to the assembled media at the match.
"When you say things in the press, you offend someone somewhere down the line. If you tell the whole truth, you offend the players, the supporters or the chairman and directors. We had to stay positive because there was too much negativity around this football club."
Sheffield United expect defender Kyle Bartley, on loan from Arsenal, to be out for up to two months after breaking a cheekbone in the 1-1 draw at Nottingham Forest.