Chelsea dumped Middlesbrough out of the FA Cup in extraordinary circumstances at Stamford Bridge.
The Londoners played the last 24 minutes with ten men when goalkeeper Carlo Cudicini was red carded following a goal-line tangle with Boro striker Dean Windass.
Referee Mark Halsey consulted assistant referee Paul Vosper as he tried to make sense of a 15 man pile-up in the Chelsea goal.
Hasley must have felt that Cudicini's apparent knee into Windass merited a straight red card.
Windass, for his part, was booked for the initial challenge on the Chelsea goalkeeper that appeared to be a left elbow into the Italian's chest after he failed to latch onto Geremi's free kick.
Middlesbrough had most of the second-half possession but they failed to use it well after Chelsea had scored the decisive goal five minutes before half time.
Mario Stanic latched onto a side-footed pass from Jimmy Floyd Hasselbaink and the Croatian slotted home an excellent left-footed shot from just outside the penalty area, past the despairing dive from Mark Schwarzer.
Chelsea coach Claudio Ranieri was amazed with the sending off. "From the bench, I did not see anything," admitted the Italian after the game.
"But from the video replay Carlo did nothing at all. He stood up, and the referee was straight there.
"We will appeal. The video was very clear and I'm sure that it will clear him. Carlo is not an aggressive player.
"Carlo just looked at the player. He must have very dangerous eyes. But I'm not angry.
"We played very well, especially in the first half. The players reacted very well to the situation.
"Sometimes I play uneven teams in practice matches, but in the heat of a match like that, it's very different." Steve McClaren, Middlesbrough manager was understandably disappointed by the result and said that he did not see the key incident of the game.
"I didn't see anything," he admitted. "There were too many players in the way.
"Dean Windass didnÂ’t tell me anything about it. But the FA Cup is all about passion, commitment and none exemplifies that more than Dean Windass. I felt his challenge on Cudicini was fair." Middlesbrough had only one effort on target in the whole game and that was a tremendous strike from Geremi which was expertly saved by substitute goalkeeper Ed De Goey two minutes from time.
Chelsea had the lion's share of the efforts and even with ten men, counter attacked well.
They could have made it 2-0 when substitute Boudewijn Zenden ran the length of the Boro half before slotting the ball wide of Schwarzer only to see it clip the keeperÂ’s right-hand post.