Joey Gallo stepped up to the plate in the eighth inning of a tie game with two outs and the bases loaded.
Midland had just brought in Omar Duran to retire Frisco's left-hander slugger. But it didn't faze the top Texas prospect, who took the southpaw deep over the right-field fence.
"It was pretty special. I didn't have a hit before earlier in the game and I didn't have a hit yesterday, so it was good to get the lead [and] hit a grand slam," the 20-year-old said.
Gallo's slam -- his second of the season -- boosted the Double-A RoughRiders to a 6-2 victory over the Missions, putting a damper on the fact that San Antonio's Kent Matthes homered for the fifth time in four games.
"I just wanted to somehow get the run home," Gallo said. "They brought the lefty in to face me and I knew it was going to be tough. I was just looking for something hard to hit and to try to adjust to off-speed pitches."
The blast was Gallo's 16th with Frisco and 37th overall -- including his time with Class A Advanced Myrtle Beach -- keeping him atop the Minor Leagues for the second straight season.
"To me, it's not important at all. Honestly, I kind of want to get better every day. If the home runs are there and I lead again, that's great, if not that's fine too," he said. "I'm just looking to develop and be a Major League player."
After a nine-game homerless stretch -- which tied his season high -- Gallo has been making up for lost time with six long balls over his last eight games. Facing Midland helped the Nevada native break out, as he smacked his fifth dinger in 11 games against the RockHounds.
"I kind of just keep seeing the ball pretty well. I was struggling a little bit before that, so I was kind of due for it. I've been having good at-bats," MLB.com's No. 9 overall prospect said. "I think it's just one of those things ... every time I'm feeling great when I'm facing [Midland] or I'm just kind of in a groove. So far this series, they've had my number though."
The 2012 first-round Draft pick went 0-for-5 with three whiffs in the series opener Monday, but made a few adjustments heading into the second meeting. While he leads the Minors in homers, there is still plenty Gallo wants to improve on in order to reach the Majors.
"The main thing is the strikeouts -- I'm working on that and trying to put the ball in play a little more, but that's a little harder for me because I'm a bigger dude, a power hitter," he said. "I just want to put together better at-bats."
Matthes slugged a two-run shot in the fourth. The left fielder has tallied nine hits and 15 RBIs during his four-game homer streak.
Newly acquired Jake Thompson -- the Rangers' No. 6 prospect -- allowed two runs on two hits while striking out five over four innings before turning the ball over to Alex Claudio (2-2), who spun four one-hit frames. Keone Kela struck out two in a perfect ninth to close out the game.