Is it possible to earn respect from the schools worst behaved student?

So let me start off by saying I’m fairly new to subbing. Despite my lack of experience, I’d like to think that my personality and having a family full of teachers has given me a solid foundation as I enter the field of education. I have been working at an elementary school as a “building sub” and up until today, I have had nothing but great classes (some were poor listeners but that’s it). Today I was the “resource teacher” and worked with students 3-5 who struggle with keeping pace with their class.

Now here’s why I am asking the question. In my first morning group, I had a 3rd grader who you was bad mannered & a loud mouth. My method with these types of children is to try & relate to them in some capacity and point out the poor behavior instead of being firm & strict right away. This worked out OK in the morning but when he came back for reading in the afternoon it was like a switch was flipped.

The afternoon session started with him not paying any attention. After constantly telling him to follow along, he sat down but immediately started to mock an introverted classmate for stuttering when reading. I told him to knock it off now & told him that he is being a bully. Even the other kids were telling him to be nice & stop distracting them. Then came the explosion…

After leaving his seat during the middle of our read along, I told him to leave the room & go sit in the hall. He told me no and that “you’re not Mrs. _. You’re not even a real teacher. You can’t tell me to do anything.” To which I raised my voice and firmly said “I don’t care who you’re regular teacher is. I’m the adult in this room & although I’m not Mrs. _, I am still a teacher and when I tell you to do something, you are to do it. If you don’t want to go in the hall, I’ll gladly walk you down to the office.” He then replied, “I’d rather go to the principals office.” So I said, “okay let’s talk a walk on down.” I made the mistake of not walking him all the way because I didn’t want to leave the other kids unsupervised which resulted in him not going & catching him in the hall minutes later. I could tell he regretted not listening (had teary eyes) so I asked if we could start fresh & if he could start behaving. He agreed. Then not even 5 minutes later he made fun of a student right in front of me so I gave up & told him to go back to his classroom. He resisted at first but after raising my voice again he left the room.

So finally, my question. Is it possible to earn the respect of a child this disobedient & disrespectful? I know that being a substitute plays a factor but FWIW, I’m a 6’3 male and have the support of just about every teacher in the school. It’s not like I’m an elderly woman who has a hard time being an enforcer (no disrespect towards the many wonderful elderly female substitutes). What else can be done? What could I have done differently/better? I know I could’ve done things better but in the moment it’s hard to know exactly how to go about an unexpected situation like this with a 9/10 year old.

TLDR; A 3rd grader tried to see how much he could get away with me as a sub. The child was bullying other kids & refusing to do what I was telling him to do. He questioned my authority & was trying to play chicken with me about going down to the office. Ended up kicking him out of the room & sending him back to his classroom teacher.