Ole Gunnar Solskjaer has told his Manchester United team they need to wise up after Crystal Palace snatched a surprise late victory at Old Trafford on Sunday.
Daniel James appeared to have salvaged a point for United with just a minute of regular time remaining, but United could not see the game out and Patrick Van Aanholt earned Palace a first league win at Old Trafford in 30 years as he finished off a swift counter-attack three minutes into time added on.
The late drama came after Marcus Rashford missed a 70th-minute penalty, having taken over spot-kick duties from Paul Pogba, who also missed a penalty in Monday's 1-1 draw at Wolves.
"We have to learn and we have to learn quickly," said Solskjaer. "From the last two games we should have got six points out of six if you look at the games as a neutral.
"We're two missed penalties away from sitting there smiling, happy with nine points."
United enjoyed more than 70 per cent possession against Palace and had 22 shots at goal, but only James really threatened Vincente Guaita's goal, seeing a first-half shot blocked by Van Aanholt in front of the goalkeeper before bending in his late equaliser.
However, Palace took a 32nd-minute lead with their first chance of the game, a route-one goal as Jeremy Schlupp beat Victor Lindelof to Guaita's long punt forward to leave Jordan Ayew one-on-one with David De Gea.
"We didn't have enough urgency and penetration in the first half until they scored," Solskjaer said. "They never looked like creating anything. We felt maybe it was too easy. That's when you need that tempo change.
"I thought we did that in the second half, we were excellent in that respect with more pressure, more chances, more urgency, but of course you've got to hit the target and score the goals when you have those moments."
United's struggles in front of goal raised further questions about the decision to let Romelu Lukaku leave without replacing him.
The 17-year-old Mason Greenwood came off the bench in the second half, but Solskjaer was otherwise short of options.
Alexis Sanchez was not in the matchday squad as he continues to be linked with a move away from the club before the European transfer window closes.
"Alexis is a quality player," Solskjaer said. "We don't have loads of options. If there is an offer that's good enough for the club and him maybe he will go, but if not then he's still our player and he's a quality player.
"He's been training well and there's no doubt about his quality so let's see."
While Solskjaer was left to rue his side's profligacy in front of goal - and pointed to two possible penalty decisions which did not go his side's way - Palace boss Roy Hodgson enjoyed a rare success for the Londoners at Old Trafford.
"The key was the defensive discipline, the shape of the team, the enormous work-rate and effort," Hodgson said. "We did well to stick to the script at all times.
"We were getting asked a lot of questions which we knew we would. They have a wealth of talent and we knew if we didn't seal the spaces and make certain that when we lost the ball we got back in our shape and only let them have the ball in the less dangerous areas they would score a goal.
"We rode our luck with the penalty a little bit. When they got that penalty I thought, 'This is going to be tricky for us now if they score this'.
"When we got away with that I was rather hoping to see it through 1-0 but we saw it through 2-1 thanks to a good bit of work from Wilfried Zaha and James McCarthy."