It was the third crowd over 15,000 at new Cubs Park, which opened this year. The Cubs set the Cactus League high 15,243, on Thursday against the Mariners, and have three home games remaining this spring.
Chicago's Anthony Rizzo had three hits, including a RBI double in the third and a RBI single in the fifth.
Edwin Jackson, who will follow Jeff Samardzija in Chicago's rotation when the season opens, gave up four runs on eight hits over five innings while striking out seven.
Kristopher Negron singled and Phillips walked with one out in the Reds' first, and one out later, they scored on Bernadina's home run. Bernadina now has hit safely in 12 of his 18 games.
"It's just a matter of location," Jackson said. "Overall, you continue to battle to keep the team in the game. They definitely made me work today, which was good. I needed to get some work in. If you're going to have a shaky start, I guess you'd rather have it in spring."
The Cubs loaded the bases with one out in the first and tallied on Nate Schierholtz's sacrifice fly to close to 3-1.
Bernadina, who is trying to make the Reds roster as an extra outfielder, delivered again in the third, hitting an RBI single with two outs, to go ahead 4-1. He now has eight RBIs and three home runs in his last six games.
"He put together a couple good at-bats today," Jackson said of Bernadina. "You just have to keep battling and keep the team in the game, and when you come out of the game, let the game be within striking distance."
Rizzo answered in the Chicago third with a one-out RBI double off lefty Tony Cingrani. Justin Ruggiano tripled with one out in the fifth and scored on Rizzo's single to close to 4-3.
Billy Hamilton tripled to open the Reds' seventh against Hector Rondon and scored on Negron's single.
Jackson found out Saturday where he would be slotted in the order. It didn't matter, the right-hander said.
"One, two, three, four, five -- we all have to have the demeanor that we're the ace that day," Jackson said. "When you have the ball, you have to be the best pitcher on the field. You can't worry about where you are in the rotation. As long as you know you're getting the ball every five days, you're giving your team a chance to win, that's the bigger picture."
Up next: Jason Hammel will make his third Cactus League start on Sunday when the Cubs travel to Phoenix to play the Athletics at 3:05 p.m. CT. The right-hander has stayed on track with a Minor League start in his last outing, throwing 75 pitches. Mike Olt is scheduled to make his second straight start at third base, the first time he will do so. Olt has been slowed this spring with soreness in his right shoulder. The game will be broadcast on WGN TV and on Cubs.com.