Arsenal's performance against Chelsea on Saturday was arguably their best of the season so far.
Not only did the Gunners score two decent goals and create the better chances, but they recorded a clean sheet after a fantastic defensive display.
Laurent Koscielny - who scored Arsenal's second goal - and Sokratis Papastathopoulos proved to be a solid centre-back partnership and kept Eden Hazard quiet.
Meanwhile, full-backs Hector Bellerin and Sead Kolasinac added plenty of threat going forward and helped keep things tight when Chelsea were attacking.
Unai Emery got his tactics spot on against Maurizio Sarri's side, though there was one damp note during the game.
Having only just returned from a calf strain, Hector Bellerin suffered a nasty-looking knee injury in the 70th minute at the Emirates Stadium and had to be stretchered off.
The 23-year-old had no one around him when he went down screaming and clutching his knee, so it's suspected ligament damage is involved.
Speaking in his post-match press conference, Emery said they will wait for scans to reveal the full extent of Bellerin's injury - but initial signs aren't good.
"We have to wait but his knee, the first prediction is it can be an important injury," said the Spaniard, per Goal. "I hope not, but first impressions are not positive."
And on potential replacements, Emery added: "We have Ainsley [Maitland-Niles]. He played well [against Chelsea] and can help us.
"Also [Stephan] Lichtsteiner is another player who can play there. We have the players. Don't forget [Carl] Jenkinson, who has played some matches and can be used if we need him."
Arsenal fear that Bellerin could be out for the rest of the season but according to Sky Sports, they won't be looking to bring in a new right-back this month.
A close-up video has now emerged of Bellerin's injury and it clearly shows the gruesome moment his knee popped. Check it out below.
Poor lad - it's no wonder Arsenal are concerned.
Bellerin was phenomenal against Chelsea with his speed and creativity down the right, which will certainly be missed over the coming months.