ST. LOUIS -- A’s manager Bob Melvin had the hot hand on Tuesday night.

Melvin, who previously managed the D-backs for four-plus seasons, pulled out some of those National League tactics to guide Oakland past the St. Louis Cardinals, 7-3, at Busch Stadium in a game that certainly had a senior-circuit feel.

• Box score

Chad Pinder and Marcus Semien hit back-to-back home runs to jump-start a six-run fifth inning. Matt Olson also homered, giving the A’s 124 at the season’s halfway mark, a pace that would break the franchise record of 243, set in 1996.

Khris Davis had a pinch-hit two-run double and Stephen Piscotty had an RBI single during the fifth-inning rally as Oakland won for the sixth time in its last eight games.

The timely hitting erased an inefficient start by Chris Bassitt, who went a season-low 3 1/3 innings. He threw 94 pitches while allowing three runs on four hits and four walks.

The short outing by Bassitt forced Melvin to get creative with double-switches, coax strong efforts out of the bullpen and even use pitcher Tanner Anderson as a pinch-hitter with the A’s bench depleted.

“It’s fun to do a National League game every now and then,” Melvin said. “Early on, we got into a little bit of a pickle with where we were. It was more the pitch count off of Bassitt more than anything else. I think there were upwards of 30 foul balls off of him.”

Here are three moves by Melvin that helped shape the A’s victory:

1. Double-switching to get Pinder into the game

Melvin’s moves started in the bottom of the fourth, when he lifted the struggling Bassitt in a double-switch, putting Pinder into the game at second base in the nine slot. Pinder, the second man up in the fifth, drove a 92 mph fastball from Cardinals starter Jack Flaherty into the upper deck in left field to tie the game at 3.

“I went up there with the mindset to get a pitch just to move him over to third, not to do too much,” Pinder said. “The first pitch he threw me was a four-seamer in that had a little bit of cut. I was just trying to get my timing down a little bit there. He ended up throwing pretty much the same exact pitch the next pitch, and I was able to put a good swing on it.”

The drive continued a hot streak for Pinder, who went 3-for-4 on Sunday after going 3-for-23 in his previous eight games.

Pinder is often used as a pinch-hitter, but this was the first time he was part of a double-switch.

“Pinder’s a guy, it’s easy, you look for ways at times to get him into the game,” Melvin said “He’s contributed to this team in so many different ways.”

2. Pinch-hitting Davis in the fifth

Melvin was asked before the game how he would use Davis, the A’s designated hitter, in the NL park. The plan was for him to come off the bench on Tuesday and start in the outfield on Wednesday.

Part one of the plan played out to perfection, as Davis pinch-hit for reliever J.B. Wendelken and smashed a two-run double to right-center to cap the A’s six-run rally.

“Pinder with the homer off the bench and K.D. with that pinch-hit, those are huge hits and not easy to do and not something we’re really accustomed to doing so early in the game,” Piscotty said.

3. Perfect use of the bullpen

Five A’s relievers combined for 5 2/3 scoreless innings. Wendelken (1-1) got Bassitt out of a two-on, one out jam in the fourth to earn his first Major League win.

“He’s not in that situation often,” Melvin said. “One, it’s early in the game, and two, it’s with guys on base and it’s the starter’s runs. If that gets away from us right there, it’s a whole different game.”

Yusmeiro Petit pitched two scoreless innings and struck out three.

“He’s been in those situations so many times that you almost expect him to do it all the time,” Melvin said. “We needed a couple innings out of him and he gave us that so that was key to bridge the game to the last couple of guys.”

Joakim Soria, Lou Trivino and Liam Hendriks shut the door. Soria pitched in his 674th Major League game, the most by a Mexican-born pitcher.

“These guys are amazing,” Wendelken said. “They’re hard-nosed and they get right after guys. That’s what you want from your relievers.”