The 12-round lightweight fight featured a strong performance from Garcia to a crowd of 14,459 as he landed an early power punch that sent Tageo to the canvas in the second round.
Once both fighters found their rhythm, Garcia systematically broke down the Ghanaian boxer as he landed precise punches to the head and body. Tagoe tried his best to keep his distance using an ineffective jab but Garcia visibly hurt him in the 10th round.
The Ghanaian fighter resorted to holding Garcia to prevent further punishment but the judges ruled in Garcia's favour with scores of 119-108, 118-109, 119-108 for a victory by unanimous decision.
"He was making it difficult for me to end it," said Ryan Garcia. "He was crafty with the holding, and I was trying to get him off me, and he was moving a lot; it was a new experience.
"I think I have to cut the ring off better with a guy who will keep moving all 12 rounds. I made sure to get him in the body a lot and used my left hook to hurt him. I have a lot of love for San Antonio. It was great that after a year and a half layoff, I was received by such a great crowd. It's a blessing. I wanted to knock him out, but he was very crafty. At the moment, I could feel like I hurt him, but he really can take a punch."
"First of all I want to thank my team," said Emmanuel Tagoe. "I know the reason why I lost. I didn't throw my right arm. He came forward but I couldn't get any points from pushing. I think I'm going to go home and sit down with my team. Ryan Garcia is a good boxer."
"I think Ryan did a fantastic job, after a one-and-a-half layoff," said Oscar De La Hoya, Chairman and CEO of Golden Boy. "He fought a tough guy from Ghana with only one defeat, he was slick, he was tough, he was surviving the whole night. Ryan almost had him out but I am glad Ryan went 12-rounds, it was a great experience."
"In between rounds I was just telling him you've got to track him down," said Joe Goossen, Trainer to Ryan Garcia. "He's not going to engage you just have to keep the pressure on. He's a tough kid.
"He only has one loss in the beginning of his career. He's been on a win streak for a very long time. He has a great chin. He was in great shape and he came here to win. He didn't come here to lose. But after a while he was not trying to win, he was just trying to survive.
"Ryan was then trying to track him down and trying to catch him. Tahoe was not being very agreeable and he didn't engage to fight a lot. Who will we fight next? I take a back seat to all of that. They don't come to the gym and tell me how to train my guys and I don't go to their office and tell them how to make fights. When they throw something g at me I say that sounds good to me and we go to work."
Garcia is hoping to become world champion in 2022 and will be keeping tabs on the winner of George Kambosos Jr and Devin Haney. The pair are fighting in June to determine lightweight's undisputed champion.