Paolo di Canio has warned his Sunderland players their stunning derby victory at Newcastle will count for nothing if they slip out of the Barclays Premier League.
A shock 3-0 win at St James' Park, the Black Cats' first for 13 years, eased them three points clear of the drop zone - just two behind their hosts - with five games remaining, and handed the 44-year-old Italian his first success since replacing Martin O'Neill.
However, Di Canio knows they must put a glorious day on Tyneside to one side as they attempt to complete the job they started in such style.
Asked if the win at St James' Park was the best of his managerial career, he said: "Yes.
"I can't forget that I was manager at Swindon - it was my start and it was crucial. I won the league, I won many important games in the cup - when you are a League Two side and you beat Wigan, a Premier League side, it's an important moment for the club's history.
"But when you arrive at the top - because the Premier League is the top league in the world in my opinion, this is why I want to stay in England, because I love the people, I love the league, I love the atmosphere, the fans - and you win one of the hottest derbies in the world...
"It's difficult to find two cities very close, 15 miles [apart] that play at the top level, and they fight for the kingdom in this area.
"Today we won 3-0 away from home, three points, it's a fantastic moment.
"Now I have to tell you as a single game, it's the most important game for me - but it's nothing if we don't stay up."
Sunderland's need was pressing as they arrived on Tyneside, and the omens were not good with only one win in 16 derbies home or away.
However, they left as deserved victors on a day when Alan Pardew's men simply did not turn up
Stephane Sessegnon's fine 27th-minute strike gave them a deserved half-time lead, and after Papiss Cisse had a 61st-minute equaliser wrongly ruled out for offside, the Black Cats flexed their muscles once again.
Adam Johnson, whose first season on his native Wearside has been testing to say the least, beat substitute keeper Rob Elliot from distance with 16 minutes remaining, and David Vaughan made sure eight minutes later with a stunning swerving strike.
Pardew, whose side slipped out of the Europa League despite drawing with Benfica on Thursday evening, said: "It was a tough day, really.
"They looked like a team who had worked all week on us, and we looked like a team who had had a really tough game on Thursday night.
"We looked a little bit tired in our minds and in our fitness and in our application to the game, and we were always struggling in that game."
Pardew's mood was not improved by the loss of keeper Tim Krul for the rest of the season with a dislocated shoulder.