Alexandre Lacazette has pinpointed the problem Arsenal must overcome despite their 2-1 win over Tottenham at the Emirates.
The Gunners claimed all three points after coming from behind to beat their biggest rivals.
But it did not start their way when Erik Lamela scored an outrageous rabona goal with their first attempt on target.
However, that was about as good as it got for Spurs as Arsenal asserted their dominance.
The home side had earlier hit the bar through Emile Smith Rowe with a thundering effort but their fortunes changed just before half-time.
After his stunner against Olympiacos in the Europa League this week, Martin Odegaard grabbed his first Premier League goal when his deflected effort beat Hugo Lloris.
© Julian Finney/POOL/EPA-EFE/REX/ShutterstockAlexandre Lacazette scored from the penalty spot to give Arsenal the win
Spurs' second half was not much better while Jose Mourinho bemoaned a penalty that was awarded to the Gunners.
Davinson Sanchez was adjudged to have fouled Lacazettemin the box and Michael Oliver pointed to the spot.
The Frenchman stepped up and made no mistake to send Lloris the wrong way and score his 12th goal of the season.
But while Arsenal claimed all three points, Lacazette has warned his team-mates that they cannot keep giving up winning positions.
With Tottenham pushing late on, there was a worry that the Gunners would throw away another victory.
When asked about those nervy moments, Lacazette said: "It is stressful. This is our problem.
© REUTERSMikel Arteta will have decisions to make following Arsenal's clash with Tottenham
"When we are winning we struggle to manage the game at the end. We need to improve.
"But we won and now we can think of Thursday. It is important to win this type of game.
"We are lucky to get the penalty, I think. But of course I am happy.
"Back in the days I have taken a lot of penalties against him [Hugo Lloris] but I was confident."
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