Nicolas Nkoulou says Arsenal's last-gasp victory over Marseille at the Stade Velodrome on Wednesday night left the French side 'truly shattered'.
Aaron Ramsey scored a stoppage-time winner to seal the 1-0 success and fire the Gunners to the top of UEFA Champions League Group F.
Marseille were content to sit on the goalless scoreline, knowing a draw would keep them in first place, so Ramsey's late effort, after he was left unmarked at the far post when a cross was swept over from the right, crushed home hopes.
Defender Nkoulou said: "I'm still feeling the shock of the defeat. The scenario is very bad. We weren't great but we weren't terrible either.
"We paid the price for letting our attention slip once."
A sliver of consolation for Marseille came with news that Borussia Dortmund had lost away to Olympiakos in the group's other game, meaning Marseille have a three-point cushion over their nearest challengers, who are now the Greek side.
"The Dortmund result still lets us believe. We are disappointed but we hope to get going again in the league from Saturday," Nkoulou said on Marseille's official website.
"We are truly shattered (by the result), we'll have to show that we are men and go looking for three points against Ajaccio.
"I am hurt but I won't dwell on it, there's a match coming up on Saturday."
Midfielder Mathieu Valbuena also believed the late goal from Ramsey was cruel on Marseille.
Valbuena said: "The worst has happened. It's very hard to digest a defeat like that. We're all stunned, upset.
"Frankly we played a good match, there was a good spirit in the team. We didn't deserve the defeat, unlike in other games."
Marseille boss Didier Deschamps was left frustrated by his side's late failure, having survived one late chance before Ramsey's strike.
"It was a game of not many opportunities and this is cruel and disappointing for us," said Deschamps.
"We are very disappointed to lose this game. We had a warning right before the goal with Robin van Persie.
"I was angry because I had warned them. One point would have been good for us."