CINCINNATI -- Brandon Phillips did something Thursday night that no major league hitter accomplished since at least 1920. However, the second baseman provided only a portion of the offense for the suddenly hot Cincinnati Reds.

Phillips hit a pair of three-run home runs and had a career-high seven RBIs, and left fielder Marlon Byrd added a three-run shot as the Reds pounded the Pittsburgh Pirates 15-5 in the opener of a four-game series.

Since 1920, when RBIs became an official statistic, Phillips is the only major league player with two homers, four hits, seven RBIs and two steals in a game, according to the Elias Sports Bureau.

"I was very surprised myself. I could've sworn Willie Mays or Hank Aaron ... somebody like that did it," Phillips said. "I'm really feeling myself right now. As a team, we're playing really good baseball. We're all just trying to finish up strong. We still believe in ourselves."

First baseman Pedro Alvarez homered for Pittsburgh (59-42), which remained winless in four games at Great American Ball Park this season while dropping to 2-8 overall against the Reds.

Cincinnati (46-54) won its third straight game after taking two of three at first-place St. Louis.

Right-hander David Holmberg (1-0) was recalled from Triple-A Louisville to take Johnny Cueto's spot in the rotation after the Reds ace was traded to the Kansas City Royals on Sunday. Holmberg allowed two runs and five hits in six innings.

"I had to pitch like it was a 0-0 game," Holmberg said. "I try to go out, be aggressive and throw strikes, pound the zone. There were some long innings which is tough. I just tried to stay loose."

First baseman Joey Votto continued his torrid pace, going 3-for-4 with a double and two walks to pace a season-high, 19-hit Cincinnati attack.

Both of Phillips' homers came off right-hander Deolis Guerra. It was his 11th career multi-homer game.

Guerra allowed six runs and seven hits in 1 1/3 innings. He has allowed at least one homer in five of his past six outings.

The right-handed reliever came on in the fifth inning to replace A.J. Burnett, whose start was concerning for the Pirates. Burnett (8-5) allowed seven earned runs after allowing more than three just twice this season. In 4 1/3 innings, he yielded eight runs on 10 hits and two walks.

"I don't know," Pittsburgh manager Clint Hurdle said when asked about pushing back Burnett's next start. "That's why I'm going to wait, sleep on it, talk to him and watch some videotape."

Burnett never found his rhythm, relying mostly on a fastball that didn't have much pop.

Following back-to-back singles with one out in the first, Byrd launched Burnett's 3-1 pitch an estimated 438 feet to center for a three-run homer that opened the scoring. It was Byrd's 17th home run of the season.

Pittsburgh got a run back when Alvarez hit his 15th home run with two outs in the second, but Holmberg mostly kept the Pirates at bat.

"He used his defense," Reds manager Bryan Price said. "Had good command of his fastball inside. It's not always easy to pitch with a big lead."

Cincinnati gradually put the game away.

Votto doubled and scored on right fielder Jay Bruce's sacrifice fly in the third.

Billy Hamilton reached on an infield hit, stole second and third (giving the center fielder 49 steals for the season), then scored on Phillips' single against a drawn-in infield, making the score 5-1.

In the fifth, Holmberg collected his first career hit, a single, putting runners at first and third. A throwing error by Alvarez allowed a run, boosting the margin to 6-1.

"That's what I had, man," Burnett said. "I'm 38. That's what I had. It's sad."

Price said, "A.J. Burnett has been tough on us. He's been tough on everyone in our division. There were a lot of guys with good days (on offense) for us."

After Burnett exited, Phillips hit his sixth homer of the season, a three-run bomb off Guerra, and the rout was on.

Later in the fifth, Bruce delivered a two-run double off Guerra to make the score 11-1.

In the eighth, outfielder Jaff Decker became the first Pirates position player to pitch in a game since Travis Snyder on June 18, 2014, vs. Cincinnati. Decker gave up two hits but threw a scoreless inning.

NOTES: Pittsburgh acquired RHP Joakim Soria from Detroit in exchange for minor league SS JaCoby Jones. ... The Pirates sent INF Justin Sellers to the Chicago White Sox for a player to be named or cash. ... Pirates RHP Vance Worley was designated for assignment to make room on the roster for RHP Joe Blanton, who was acquired early Thursday morning from Kansas City for cash considerations. ... Cincinnati optioned C Kyle Skipworth to Double-A Pensacola, placed RHP Nate Adcock on the disabled list with a right elbow injury and recalled RHP Keyvius Sampson from Louisville.