Mangini homered, doubled and plated three runs as the BayBears beat the Jackson Generals, 7-2, in Game 2 to even up the best-of-5 Championship Series.
"It's big to bounce back. Now we go back to Mobile with home-field advantage and the momentum," Mangini said.
"[James] Paxton is a great pitcher and he handled us pretty well for eight innings yesterday. But the good thing about the playoffs is every day is a new day."
Mangini broke a scoreless tie in the fourth inning when he laced a one-out double to left field to score Alfredo Marte, who had led off the inning with a two-bagger of his own.
"We were kinda at a standstill for a couple innings, then we started putting some good at-bats together in the fourth and fifth," said Mangini.
"I think it was a cutter away first pitch, then another cutter over the plate. I stayed with it and hit it out to left field."
An inning later, he capped a five-run fifth with a two-out homer to right field. It was his first longball of the postseason and his first as a member of the BayBears.
"I think it was just a fastball up and in. There were two outs and a guy on third. It can change the momentum if you drive those runs in.
"They threw a fastball up and away for a ball and I figured they didn't want to go to 2-0, so I stayed aggressive. It was huge. It's big to get some early runs and give your pitcher some support. We had guys on base for a couple of my at-bats, so I just had to stay within myself and capitalize on it."
The series heads to Mobile for Games 3 and 4. The BayBears would also host Game 5, should the clubs split the next two contests.
For 26-year-old Mangini, released by the Tampa Bay Rays in mid-August and then signed to a Minor League deal by the D-backs five days later, the chance to win a Double-A championship still has a strong appeal, even though he played in the Majors in 2010 and at Triple-A Tacoma and Durham over the last three years.
"Any time you're playing for a championship is special," he said. "The last championship I won was in 2010 in the PCL, so I have a little bit of experience. I played a full season just like everyone else [this year]. My season was a bit different, but I knew coming here they would be in the playoffs.
"We just have to continue to scrap and claw and get guys on base. We have to keep the momentum on our side. It's all about scoring runs in the playoffs. It takes a whole team effort."
Mangini's offense proved enough for Mobile starter David Holmberg (1-0), who allowed two runs on five hits over 6 2/3 innings. He struck out two batters and issued two walks. Even Marshall, Eury De La Rosa and Kevin Munson did not allow a hit over the final 2 1/3 innings to seal the win.
James Gillheeney (1-1) took the loss for the Generals. He yielded six runs on nine hits while fanning four batters over five frames.