The Gunners forward was handed the armband in the 2-0 victory over West Ham, and apart from one spot-kick miss, he didn't let Mikel Arteta down.
He was a handful for the opposition defence all game and played a sublime pass to Gabriel Martinelli to break the deadlock shortly after half-time, before Emile Smith Rowe sealed the points for the Gunners.
The Frenchman was relentless in his work rate. He made more tackles than any other player on the pitch (five) and attempted more than any other too (nine).
He didn't give Issa Diop and Craig Dawson's a moments rest all game and it's not inconceivable to suggest he succeeds Pierre-Emerick Aubameyang as the skipper at the Emirates, with his pal axed from the role earlier this week.
Mikel Arteta was certainly impressed with the Frenchman as he praised him and his side's display in general following the victory at the Emirates, which saw the Gunners leapfrog West ham to go fourth.
"I think they were terrific", Arteta told talkSPORT of his side's performance after the match.
"I think Lacazette was terrific. I think Granit [Xhaka] and Thomas [Partey] were terrific.
"The contribution of the whole team, individually and collectively, it was a really strong performance."
Lacazette demonstrated that he has so much more to give in an Arsenal shirt.
The problem is, he may not be at the club for much longer.
The 30-year-old is out of contract at the end of the 2021/22 season, meaning he can sign a pre-contract agreement with a foreign club next month.
The lure of the captain's armband, however, could convince the Frenchman to stay.
His man-of-the-match display will certainly make a contract decision easier for the Emirates hierarchy.