I got into a fight 2 hours ago. How important is strength in a street fight? boxing?

How much does being strong matter in a physical confrontation with a stranger? I'm talking about overall strength aka general strength. I ask this because I got into a fight at the market moments ago with a short Mexican dude. He got disrespectfully close to me as I was paying for my groceries "BACK OFF!" I told him loudly. "Shut the **** up and pay for your ****," he barked. At that moment I said **** the groceries. "Back up, you idiot." As soon as I uttered the word idiot, he pushed my shoulder, displacing me and causing me to stagger. I quickly regained my balance and retaliated with a stronger push. Before I could bring my hands back he rushed me, catching me off balance. He grabbed me with overwhelming force and was manhandling me even though he is only about 5'7 and I'm 6'0 barefoot, 6'1 with shoes on. Instantly I knew I was in trouble. For a little dude he was really strong and energetic. I got scared. I felt like I was drowning. My arms and body got tired from all the grappling. I felt like I was going to be choked unconscious so I started screaming for help. "HELP!" "HELP!" A black guy in his thirties wearing black shoes, slacks, dress shirt, and tie heard me panicking and offered only advice to me and not help pulling the guy off me. "Just whoop his ass, my man." The guy got tired and loosened his grip on me, so I instantly bucked out of his grasp and assumed a boxing stance. He expended a ton of energy trying to hold down and choke out a bigger man. A second wind overcame me and revitalized me. I swarmed him and let my hands fly. Straight right hands, hooks, and uppercuts. The tables have turned. I was coming on strong and connecting hard punches on his face, body, and back. With his face getting cut and bruising, he retreated. I ditched my groceries and ran to my car. I've been home for two hours now and am wondering how much strength comes into play in street fighting.