Substitute Daryl Murphy's injury-time winner handed the Black Cats the derby spoils against Middlesbrough and brought a successful conclusion to their season-long fight to avoid an immediate return to the Coca-Cola Championship.

Keane, a veteran of glittering campaigns at both club and international level as a player, admitted it has been a roller-coaster season, but was delighted with the outcome.

He said: "I am just delighted for everyone at the football club. It has been a roller-coaster, a proper roller-coaster.

"I have been on some at Alton Towers and they wouldn't touch this job, I'm telling you. It is just up and down.

"We have had a long week this week after the Newcastle game. I was disappointed with the reaction of certain people, both the media and our supporters.

"We know we are short, but you shouldn't question the players. They have answered a few people today, like I knew they would.

"If they had dropped their heads - and it would have been very easy to - trust me, we would have been well adrift with Derby, that's a promise.

"But we have a good dressing room and if we didn't have a good dressing room, we would have been knackered.

"That kept us going, a good dressing room and good staff."

Tuncay Sanli got Boro off to the perfect start with a fourth-minute opener, but Danny Higginbotham levelled with two minutes.

Michael Chopra put the home side ahead in first-half injury time, but it looked like Afonso Alves' 73rd-minute strike would be enough to hand the Teessiders a point until Murphy struck.

Asked if he was relieved, Keane replied: "I'm glad it's over with, yes. My wife and kids will be.

"It's part of the master-plan, shall we say. The first part was to get promoted, which I felt was going to be easy.

"Staying in the Premier League was another challenge, but we have got another year left and hopefully that will be to improve the squad and make sure we are higher up in the table.

"We have got two games to go and we are still confident we can try to get a few points on the board and finish as high as possible."

Keane has invested £44million in his squad since dragging them back into the Premier League, and will hope to spend heavily again this summer to build upon the foundation he has established.

Asked how far short he is of where he would like to be, he said with a smile: "Sixty, seventy million? It's going up every week.

"It started at £40million and we are up to £60million now. By the end of next week, it will be about £80million.

"I will be looking for (chairman) Niall (Quinn) and (chief executive) Peter (Walker) in the next half an hour. They are in hiding."

Keane's delight was in stark contrast to opposite number Gareth Southgate's mood as he prepared for home games with Portsmouth and Manchester City with results still needed.

Southgate said: "It's the first derby I have lost as a manager, so that's painful. You don't want to be in the middle of somebody else's party when you have lost.

"But sometimes as a group, you are going to have to go through these experiences and how you come out the other side is the most important thing.

"It's fantastic for them (Sunderland) that they are secure, and deservedly so with what they have done during the season.

"Hopefully we can have a similar thing next week."