LaSalle Street was littered with debris Saturday and Sunday and helicopters hovered over the action for aerial shots that included parachutists.
The streets reopened around 5 a.m., in time for the Monday morning rush hour.
During the filming, movie fans gathered to get a glimpse of the stars, which include Shia Labeouf, Patrick Dempsey, Frances McDormand and John Malkovich.
The shoot is pumping millions of dollars into the local economy and providing jobs for about 200 people.
The film shoot heads north to Milwaukee on Monday, but it will return to Chicago later in the week. Autobots and Decepticons will be hanging around Chicago until August 19.
Weekend shoot draws crowds, closes streets
Several streets in the Loop were shut down Saturday and Sunday to accommodate the weekend shoot. LaSalle was closed from Jackson to Wacker, Washington is shut down between Wells and Clark, and Randolph is closed from Wells to Wacker.
Eight CTA buses were rerouted this weekend while production takes place.
The filming for the movie will take place primarily in the LaSalle Street Financial District. An aerial photography unit will also be flying near the Willis Tower, East Randolph Street and Daley Plaza.
Film ambassadors in yellow T-shirts fanned out Friday to let people know what is going on and to guide people around the closures.
"We came all the way from the south suburbs to see this," said Transformers fan Jerise Ricard. "We're really excited."
A normally empty lot at Washington and Franklin was transformed into a staging area for lots of fake rubble and crushed vehicles.
"It's really cool, but it looks a lot different than in the movies," said fan Grace Lasky.
The movie will showcase some Chicago landmarks, including Trump Tower, which base-jumpers will dive off of for the film.