Ronny Deila’s side made it two wins out of two in the Scottish Premiership with a 2-0 victory over Thistle away from home.
Tom Rogic put the Bhoys in the lead at the Firhill Stadium just before the half-hour mark, and Kris Commons added a second in the 63rd minute.
Over the course of the 90 minutes, Celtic had 59% of the possession, took 15 shots of which six were on target, and earned five corners.
Meanwhile, hosts Thistle had 41% of the possession, took five shots of which just one was on target, and earned one corner.
After the match, Lustig admitted that Celtic could have played better than they did.
“It is nice to come here and take three points,” the 28-year-old right-back told BBC Radio Scotland.
"We started well, playing some excellent stuff for the first 30 minutes, but after that we became a bit sloppy."
Celtic are back in action on Wednesday, when they take on Kilmarnock away from home in the Scottish Premiership.