The Cleveland infield prospect doubled and scored twice in the Peoria Saguaros' 4-0 shutout of the Phoenix Desert Dogs.
Rivero, who is batting .351 in Arizona, hit .242 with 58 RBIs and 50 runs for Double-A Akron in the regular season. He also committed 14 errors in 132 games.
"I'm just working on my hitting and my defense," he said through Saguaros teammate/interpreter Yonder Alonso (Reds). "I'm just executing now and things are falling for me. I'm very happy.
"[I'm] just trying to improve on the everyday game and become a winner."
Signed by Cleveland as a free agent in 2005, Rivero doubled in the fourth and scored the game's first run on a single by Freddie Freeman (Braves). He crossed the plate again on Zack Cozart's single in the eighth.
Rivero, who was the starting shortstop for the Eastern League-champion Akron Aeros, credited the entire team for picking up their play lately. Peoria (7-8) has won its last six games and is two games out of first place in the AFL West.
"We've been playing great the last 10 games," the 21-year-old said. "Some hits are falling in for us, and we're doing the things we need to do to win."
Cozart (Reds) doubled for the third straight game, drove in his 10th run of the season and extended his hitting streak to six games. Freeman's single gave him hits in five straight games.
Astros right-hander Wilton Lopez (1-0) earned the win in relief. He allowed one hit and struck out two in four shutout innings. Evan Scribner (Padres) fanned two in a perfect ninth inning.
Jemile Weeks, Oakland's first-round pick in 2008, hit a sixth-inning double to extend his hitting streak to six and Chris Marrero (Nationals) had two hits to raise his average to .349 for the Desert Dogs (10-5).
Grant Desme, who had homered 10 times in the previous 10 games and is batting at a .434 clip, went 0-for-4.
James Simmons (1-1) was tagged with the loss after giving up two runs on four hits in 4 2/3 innings. The loss snapped a four-game winning streak for first-place Phoenix, which holds a four-game lead in the AFL East.
Robert Emrich is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.