Alonso drove in two key runs for Peoria in the Saguaros' 6-3 victory over the Scottsdale Scorpions on Thursday afternoon.
The Reds' first-round pick in 2008 delivered a two-RBI single in the third inning to give the Saguaros a lead they would not relinquish. The Cuban-born first baseman also singled and was driven in by Jon Gaston (Astros) in the fifth inning.
"You have a guy like [the Pirates' Donnie] Veal who has been in the bigs and knows what he is doing, you just want to go up there and put a good swing on the ball and just try not to do too much," Alonso said.
Alonso, who was a Florida State League Midseason All-Star, started for the West and drove in two runs in the AFL Rising Stars Showcase last Saturday.
"Ninety-five percent of the players there go to the big leagues," he said. "It's an honor to be part of something I will remember the rest of my life."
Carlos Rivero (Indians) homered, doubled and scored twice for Peoria (12-14). The 21-year-old shortstop extended his hitting streak to seven games. Atlanta farmhand Brandon Hicks added a solo homer.
Cole Gillespie (Diamondbacks) contributed a pair of doubles and drove in a run for Scottsdale (10-15). Jose Tabata (Pirates) continued his hot hitting with a pair of singles and has six multi-hit games in his last 10 contests.
Josh Judy (Indians) picked up his second win after allowing two hits and fanning two in 2 1/3 scoreless innings of relief. Dan Meszaros (Astros) picked up his first save, striking out one in a scoreless ninth.
Pirates pitcher Donnie Veal was tagged for three runs on five hits in 2 1/3 innings in his first AFL loss. Tony Watson (Pirates) pitched a perfect frame in relief.
Robert Emrich is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.