"I look at the mirror and see what I'm doing right or wrong and it's helped me out," said Rivera, who was removed after reaching the 75-pitch limit. "I just want to practice my mechanics and that keeps me going."
Rivera, a right-hander, got in a jam in each of the first two innings. However, he calmly worked his way out of both situations.
In the top of the first, he surrendered a lead-off hit to Jacob Hanna, who advanced to third with one out. Rivera then got a strikeout and a pop up to end the threat. The first two batters reached base in the second before Rivera promptly got two strikeouts and snagged a line drive for the final out.
"I got in those two jams and then I got out of them by focusing on the catcher's glove and throwing strikes," Rivera said.
Vaquero Manager Luis Cejudo marveled at Rivera's performance.
"He's an awesome player and he showed it again for us," said Cejudo, whose team finished with two hits. "He shut them down and we got the best out of him."
Vaquero scored four runs in the second. Omar Hernandez walked on a full-count pitch with one out and the bases loaded to make it 1-0. An error by the first baseman gave Vaquero a 2-0 lead before Jacob Romero blooped a two-out bases-loaded double down the right-field line on a 1-0 pitch to extend the advantage to 4-0.
"It's the bases loaded and I was feeling kind of nervous," Romero said. "I just wanted to hit the ball."
Vaquero took a 5-0 lead in the third on a groundout that scored Michael Lemus.
Vaquero closed out the scoring in the fourth on an error by the shortstop.
Relievers Gerrardo Fuentes and Romero combined to get the final four outs.