Yasiel Puig homered twice, Cody Bellinger hit a two-run blast and Joc Pederson added a solo shot, lifting the Dodgers to a 10-2 victory over the Cincinnati Reds on a steamy afternoon at Great American Ball Park.
"The offense today was the story," Roberts said. "From the first (batter) to the eighth, we put together some good at-bats and had some big hits. Everyone on the field today gave us a chance to win."
Bellinger's homer was his National-League leading 19th, tying a major-league record for most homers in a player's first 49 career games. The Yankees' Gary Sanchez is the only other player to reach 19 homers in that span.
"I'm sort of expecting it now," Roberts said. "The homers, doubles, singles, walks ... it's the at-bat quality. He's a very talented young player with good mechanics. Cody's way ahead of schedule."
Puig homered in consecutive at-bats. He went deep in the sixth inning against Austin Brice and added his 12th homer of the season in the eighth against Jake Buchanan. It was his third career multi-home run game.
"Just trying to find the right pitch (to hit)," said Puig, via a translator. "The offense has been doing its job. Bellinger keeps hitting balls to the street. Pederson is more patient."
The Dodgers (43-26) have won seven straight games against the Reds dating to last season and are 16-3 against them since 2015. Los Angeles has won eight of nine.
"We're playing well, but we need to continue to get better if we're going to be ready for the playoffs and World Series," Puig said.
Joey Votto went 3-for-4 to extend his hitting streak to 11 games for Cincinnati (29-38), which has lost a season-high eight in a row. The Reds haven't lost more than eight straight since an 11-game skid in May 2016.
Los Angeles starter Hyun-Jin Ryu (3-6) needed 105 pitches to get through five innings but allowed only two runs and eight hits with two walks and seven strikeouts.
"He was close to being done in the third inning," Roberts said. "But to find a way to get through five innings is a credit to him. He dug deep today."
Consecutive doubles by Corey Seager and Bellinger produced a run for the Dodgers in the first inning.
Billy Hamilton showcased his speed in the bottom half of the first when he singled and raced to third on Zack Cozart's double. When Chris Taylor's throw into second got away for an error, Hamilton slid home to tie the score.
For the second straight day, the temperature at the start of the game was 90 degrees.
Things got more heated in the second inning when Reds manager Bryan Price was ejected for arguing a called third strike by home plate umpire Stu Scheurwater on Hamilton for the third out.
Hamilton tossed his bat and helmet before Price got ejected for offering choice words from the dugout. It was Price's first ejection of the season.
Taylor atoned for his throwing error with a two-run double in the third.
"There was some hesitation (by the umpire), and I didn't care for it," Price said. "You want the call immediately. The hesitation got under my skin. I just didn't think it was a good enough pitch."
Bellinger's two-run shot in the third was immediately followed by Pederson's solo shot to put Los Angeles ahead 6-1. It was Pederson's fourth homer and second in as many days.
Reds starter Asher Wojciechowski (1-1) allowed six runs (five earned) in 2 1/3 innings.
Cincinnati had three triples among its six extra-base hits but went 1-for-17 with runners in scoring position.
"The tide will turn," Price said. "We're too good of an offensive ballclub to think this will last too long."
NOTES: The Reds unveiled a statue of baseball's hits king Pete Rose outside Great American Ball Park before the game. Rose was joined by several teammates from the Big Red Machine clubs of the 1970s that won World Series titles in 1975 and 1976. ... Reds SS Zack Cozart snapped an 0-for-19 skid with a first-inning double. ... The Dodgers have clinched the season series against the Reds for the fourth straight year. ... Reds manager Bryan Price was ejected for the 10th time in his career.