After failing to collect a hit in his first two trips to the plate, Calhoun, who batted third and started in left field, unloaded on a game-tying two-run homer in the bottom of the fifth inning and then pushed across two more runs in the seventh with a single to center field.
Those hits set the stage for Calhoun's heroics in the bottom of the ninth, as the 22-year-old left-handed hitter deposited the first pitch he saw over the wall in left-center field to win the game.
Calhoun's multi-homer performance was his second this season, both while with the Express, and he's now hit 31 home runs in 127 Triple-A games overall while slashing .298/.353/.571 with 93 RBIs.
The rest of the best performances from top prospects Sunday
• No. 13 overall prospect Brent Honeywell (Rays' No. 1) fired 5 1/3 scoreless innings, allowing four hits and striking out five, for Triple-A Durham in his return from a suspension. With the Bulls headed for the International League playoffs, the 22-year-old righty concludes his regular season with a 3.49 ERA and a 172-to-35 strikeout-to-walk ratio in 136 2/3 innings (26 starts).
• No. 95 overall prospect Tyler O'Neill (Cardinals' No. 4) had another huge game for Triple-A Memphis, going 3-for-6 with a home run and five RBIs. The three-hit performance was the 22-year-old outfielder's second in as many days, and he's now homered in five of his past six contests. Overall, O'Neill has slugged 31 home runs in 2017 -- one shy of his career high -- including 12 homers in 36 games after going from Seattle to St. Louis in a Trade Deadline deal.
• Braves No. 11 prospect Austin Riley went 3-for-4 with a double in his second straight three-hit game for Double-A Mississippi. The 21-year-old third baseman has a .309/.387/.503 slash line with eight home runs in 47 games with the M-Braves after slashing .252/.310/.408 with 12 homers over 81 games in the Florida State League.
• Brewers No. 10 prospect Lucas Erceg came off the bench for Triple-A Colorado Springs to go 2-for-3 with an RBI. Promoted from Class A Advanced Carolina directly to Triple-A on Friday, the 22-year-old third baseman is 3-for-7 with a double and two RBIs in two games with the Sky Sox after slashing .256/.307/.417 with 15 homers, 33 doubles and 81 RBIs over 127 games in the Carolina League.
• Padres No. 21 prospect Michael Gettys connected on a two-run homer in a three-hit, four-RBI performance for Class A Advanced Lake Elsinore. The 21-year-old outfielder once again has shown an impressive power-speed combination this season by totaling 17 homers and 22 steals, albeit with a .256 average and 188 strikeouts in 115 games.
• Padres No. 23 prospect Hudson Potts became the third player in Class A Fort Wayne franchise history to hit 20 home runs in a season with his two-run shot in the third inning. After finishing the game 3-for-4 with five RBIs, the 18-year-old third baseman is now batting .278 with 14 homers and 46 RBIs over 65 games in the second half.
• Phillies No. 16 prospect JoJo Romero wrapped up his season with a win for Class A Advanced Clearwater. The 20-year-old southpaw tossed six strong innings, allowing one unearned run on four hits with four strikeouts to finish with a 2.24 ERA over 52 1/3 innings (10 starts) in the Florida State League. Overall, Romero finished his first full season with a 10-3 record and a 2.16 ERA in 23 starts across two levels. Logging 129 innings, he compiled 128 strikeouts against 36 walks while holding hitters to a .223 clip and yielding just four home runs.
• Pirates No. 5 prospect Cole Tucker hit a solo home run, doubled and scored two runs out of the leadoff spot as Altoona shut out Harrisburg, 6-0. The 21-year-old shortstop went 2-for-4 in the contest and has six multi-hit efforts in his past eight games, during which he's lifted his Double-A average from .226 to .264. On the season, Tucker, a 6-foot-3 switch-hitter, has produced a .277/.359/.411 line with 36 extra-base hits and 46 stolen bases in 109 games across two levels.
• White Sox No. 10 prospect Dane Dunning was nearly untouchable in Game 1 of a doubleheader for Class A Advanced Winston-Salem, firing seven innings of one-hit ball with nine strikeouts en route to recording his second shutout of the season. He threw 58 of his 78 pitches for strikes, facing one over the minimum in the outing. Dunning, 22, posted a 2.94 ERA with 168 strikeouts over 144 innings (26 starts) in 2017.