PHILADELPHIA -- Spencer Steer doesn't do anything flashy and isn't the type to play with emotions on his sleeve. But the Reds’ left fielder, who always seems to be in the middle of the offensive action, couldn't help but let out an emphatic yell as he rounded first base in the top of the 10th inning on Monday.

Why is that? Steer had just watched his drive clear the left-center-field fence for the eventual game-winning grand slam during a 6-3 win over the Phillies at Citizens Bank Park.

“It was just a really cool moment," Steer said. "I just kind of lost it right there. I was happy to come through for the squad because I felt like we played a really good game tonight."

It was 2-2 in the 10th when Phillies reliever Connor Brogdon struggled to locate. With automatic runner Bubba Thompson on second base, Brogdon walked Will Benson and then walked Jonathan India on four pitches to load the bases with no outs.

Steer was in a 2-1 count when Brogdon offered a 92 mph fastball over the heart of the strike zone.

"I don't even know how many balls I had thrown in a row before I showed him a strike. At that point, I was like, man, just throw the ball in the zone," Brogdon said. "I mean, you just can't leave a ball there to a big league hitter because he's going to hit it out."

The last Red to hit a grand slam in extra innings was Todd Frazier on June 17, 2015, vs. the Tigers.

It was Steer's first homer of the season, but he's already 6-for-15 (.400) with two doubles and seven RBIs as he comes off a full rookie season in which he led the team in homers (23) and RBIs (86) over 156 games.

“He just has a solid, consistent approach," Reds manager David Bell said. "It really doesn’t change depending on the situation or who he’s facing. He just really knows himself at the plate. It allows him to consistently have good at-bats. He came through there for sure. He got ahead in the count and stayed with what he does.”

And when the game is on the line -- even on a team with a few good men -- you want Steer in that batter's box, you need Steer in that batter's box.

"Feels nice to do something positive for the team," Steer said. "I like being in those big situations. Those are the spots I want to be in. I don’t want to shy away from those moments. To come up like that tonight was great, obviously. Moving forward, I’ll keep doing that in those spots.”

Steer, 26, can play five positions in the field but became the main left fielder this season, and he does just what's required at the moment with a bat.

"That guy can do anything," closer Alexis Díaz said via translator Jorge Merlos. "He can steal bases, he can play well defensively, he can hit the ball very hard. He’s that guy that does everything, whatever’s needed out there."

Following starter Andrew Abbott's 5 1/3 innings with two first-inning runs allowed, Reds pitching kept Philadelphia quiet. Phillies lefty starter Cristopher Sánchez had also kept the Reds quiet much of the game until a leadoff walk in the sixth inning.

Steer's opposite-field double off the right field wall ended Sánchez's night.

Christian Encarnacion-Strand and Jeimer Candelario tied the game with RBI singles. In the eighth inning, Brent Suter gave up a pair of singles before Díaz was summoned to keep the game tied at 2 with one out.

As he faced J.T. Realmuto, Díaz picked off Johan Rojas at second base. Then he struck out Realmuto with a full-count slider to escape the inherited jam.

"I really thought the game was in our hands once I threw it to second and got the pickoff right there," said Díaz, who earned the win. "I kind of knew, 'OK, this inning is mine now.' I knew we had the advantage there. And I knew I was going to be able to get out of it."

Tejay Antone was given the ball for the bottom of the 10th in a non-save situation. Antone gave up a two-out run on a comebacker off his leg but struck out Bryce Harper representing the tying run to end the game.

Cincinnati has won three of its first four games to begin the 2024 season. It has maintained its aggressiveness with an MLB-leading 11 steals but is showing plenty of power, too, with seven homers.

“Whatever it takes," Bell said. "Guys continue to have great at-bats when we need them.”