Entertainment TV AGT: Spoken Word Artist Brandon Leake Performs Powerful Black Lives Matter Poem in Quarterfinals Brandon Leake previously won judge Howie Mandel's Golden Buzzer during the audition round By Karen Mizoguchi Published on September 1, 2020 10:01 PM Share Tweet Pin Email Photo: Trae Patton/NBC The fourth and final slate of contestants performed in the live quarterfinal rounds of America's Got Talent. Heidi Klum, Sofia Vergara and Howie Mandel were back again without a guest judge or Simon Cowell, who broke his back on Aug. 8 at his Malibu, California, home when he fell off an electric bike. Hours after the accident, Cowell underwent surgery during which he had a "number of fusions and metal rod" put into his back, a source previously told PEOPLE. The last 11 acts to compete for a spot in the semi-finals were roaster Alex Hooper, hand-balancing siblings Bello Sisters, spoken word artist (and Mandel's Golden Buzzer winner) Brandon Leake, singers Broken Roots, cheerleaders C.A. Wildcats, singer Celina, Divas & Drummers of Compton, singer Kenadi Dodds, projection artists Lightwave Theatre Company and dancer Noah Epps. Leake, who is AGT's first-ever spoken word poet to compete, was among the standout performances of the night with his moving poem. The Stockton, California, native spoke about his mother's "greatest fear" about her son living in America as a Black man and honored the lives of Ahmaud Arbery, George Floyd, Breonna Taylor and Jacob Blake. "Normally death don't really bother me, I'm from southside Stockton. I'm all too familiar with how some family reunions only ever take place on graveyard grass, and a hole can be a safe haven for a soul in this mortal game of hide and go seek. But, there is something so different about Ahmaud Arbery, George Floyd, Breonna Taylor, Jacob Blake and the countless others," Leake said. "And as I stared at that screen, I couldn't help but think I was looking at a mirror image of myself being choked out for merely existing or for daring to be more than three-fifths of what them folk thought them to be. Or maybe it was simply due to they hue and in that moment I better understand my Black mother's greatest fear was every time I left her home, on the other side of her phone would no longer be her son, it would be America's most popular hashtag," the father of one said. Later, Leake emotionally said, "My mother's greatest fear is that I won't return home breathing, blood pulsing through these veins enough to still be her Pookie. My mom warned me, 'Son, don't you dare get caught at the wrong place at the wrong time with that wrong colored skin ... I need you to return home my Pookie, to be your mom.' " "Words seem to move people and myself more than anything, he's got everything," Mandel, 64, said of his Golden Buzzer winner. "America, sit quietly, listen and take it in." After the show, Mandel spoke with PEOPLE and praised Leake on the "imperative and important" message of his poem. "I believe that the biggest issue in this world, and I'm not being political, I'm being truthful, we're all in this together. We have to understand each other and be compassionate, have empathy for each other. Most of us don't often walk in other people's shoes. Brandon's words were able to take a 64-year-old white guy and put him inside the heart and mind of an African-American mother whose just saying goodbye and fearing for her son's return," he said. "I think just aside whatever this contest is and this talent show is, it's probably the clearest vision of what is going on today than what I have ever heard. If people missed this show tonight, they need to watch this on YouTube and need to share it. Everybody has to hear it. If you don't understand it and you're not moved by it, then you're not a human being." Mandel added, "I asked Brandon if his mother had heard this and he said no. She was going to watch this live on TV tonight." After the final five acts are determined for the live semifinals, next week will be the first of two rounds, with 10 acts competing each Tuesday (Sept. 8 and Sept. 15) at the Universal Studios Hollywood lots. On the following Wednesdays, (which will feature celebrity musical acts including BTS on Sept. 16), the finalists will be announced. And season 15 will conclude on Sept. 22 and Sept. 23, when a winner will be crowned during the scheduled finale. Simon Cowell Is 'Very Happy' to Be Home 1 Week After Breaking His Back and Undergoing Surgery Sofia Vergara Recalls Brother's Death During Powerful AGT Audition: 'I Can Feel Your Pain' Klum, Vergara and Mandel have all spoken to PEOPLE about Cowell's recovery. When or if Cowell, 60, will return has yet to be determined. Last week, a source told PEOPLE that "Simon's healing has been going well," and "he's recovering at home." (Kelly Clarkson and Kenan Thompson previously served as season 15 guest judges during the live shows.) "It's been great to have all those guest judges, but I do miss Simon. I wish he could've been here," Vergara said. "For me, it's my first time and I feel comfortable when he is with us. Howie and Heidi are amazing, but he's the boss!" Klum also said Cowell has been "healing pretty fast," adding, "I think he's doing amazingly." America's Got Talent airs Tuesdays and Wednesdays (at 8 p.m. ET) on NBC.