Chelsea midfielder Jorginho lamented two points dropped after his side could only draw 10-man Arsenal 2-2 on Tuesday night.
The Blues were handed a major advantage inside of 30 minutes when David Luiz was sent off for fouling Tammy Abraham in the box after a poor back pass from Shkodran Mustafi.
But Frank Lampard's side only held on to that lead for three minutes, as Hector Bellerin salvaged a dramatic draw for the visitors with a curling left-footed effort from the edge of the box.
The strike was Bellerin's first Premier League goal in 737 days, with the Spaniard's most recent effort coming at Bournemouth in January 2018.
After the game, Jorginho couldn't hide his frustration at failing to earn all three points against a rival that played more than two-thirds of the match down a man.
"We feel like we lost the game," the Italy international told BT Sport. "We had the game in our hands then in the last second conceded a goal when we shouldn't. It's hard. We need to move forward.
"I don't think it's confidence because we played well and were controlling the game. Something about concentration maybe. In these kind of games, you lose in moments. We made mistakes. That is it.
"These big games are like these. You can win and lose the game in the details."