Newcastle manager Rafael Benitez admitted his side failed to "handle the pressure" as they slipped to a 1-0 defeat against Sheffield Wednesday.
The Magpies missed the chance to go four points clear at the top of the Sky Bet Championship as they slumped to their first league defeat against the Owls since 1998.
Captain Glenn Loovens' second-half header separated the two sides as Carlos Carvalhal's play-off chasing Wednesday picked up the points at St James' Park.
"We didn't handle the pressure well," admitted Benitez.
"You always have to be disappointed when you lose, especially in a game like this when you're at the top against a good side.
"We had about three good chances before they scored their goal and we just didn't take our chances."
Benitez believes his side will have to stop being caught on the counter-attack, like they have been a few times this season.
He added: "Even after we conceded we gave them the chance to keep counter-attacking.
"This is something we have to improve on because we've had this problem in a couple of games.
"It's been highlighted by a good team but it's something we need to improve on."
Dwight Gayle, the league's top scorer, saw Owls stopper Keiren Westwood tip his strike onto the crossbar early on.
Defender Ciaran Clark then headed off target twice from corners, with the first flying over the bar before the second went wide of the target.
Scottish striker Steven Fletcher forced Karl Darlow into a top stop to tip his thunderous shot over.
Moments after the restart Darlow had to make another stellar save to keep out Fletcher with his legs.
In the 53rd minute Wednesday grabbed the only goal of the game through Dutch defender Loovens, who netted his first Owls goal, as he nodded home the rebound from Fernando Forestieri's initial header.
Wednesday looked content with a one-goal win as they kept men behind the ball after scoring and invited the hosts' onslaught.