Manager Ole Gunnar Solskjaer conceded a nightmare start to the second half was central to Cardiff City's 3-0 derby loss at Swansea City.
Kenwyne Jones spurned a pair of first-half chances for the visitors, who were seeking an historic league double over their bitter rivals.
Swansea substitute Pablo Hernandez subsequently caught out Cardiff full-back Fabio da Silva with a glorious throughball for Wayne Routledge to open the scoring two minutes after the interval.
And, after Craig Bellamy rattled the crossbar for the visitors, Nathan Dyer and Wilfried Bony sealed Swansea's triumph.
"We came in at half-time thinking that's the best first half we've played – under me anyway," said Solskjaer, who succeeded Malky Mackay on January 2.
"Coming in 0-0 here, we had the game where we wanted (it) but the start of the second half, of course, is a bitter blow.
"Then we had a good response by the lads, as they always give me. We created a few chances - Craig hit the crossbar and there was a scramble where Kim Bo (Kyung) got the ball after the free-kick and it could be a draw.
"But then they scored that second goal and it's game over."
Victory would have hauled Cardiff level on points with their neighbours, whose move up to 10th underlines the congested nature of the Premier League's bottom half.
This gives Solskjaer hope that his 19th-placed side will remain in high spirits as they turn their attention towards Tuesday night's vital home clash with Aston Villa, who sit 12th.
"League position is one thing - I think everyone that's related to the club, we knew we were going to have to battle in the situation we're in now," the former Manchester United forward added.
"Psychologically it can go both ways; I think I'll get a reaction and a response. The dressing room is obviously downbeat after a defeat against your worst enemy but we've got a massive game on Tuesday against Villa, who are also in a similar situation to us.
"So we’ve got to respond and bounce back for that one and I'm sure they will because of the characters and personalities in there. That’s the way they are."
|20||J. de Guzmán|
|Coach: G. Monk|
for M. Emnes 46'
for J. de Guzmán 69'
for N. Dyer 88'
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