Wandy Rodriguez(6-3) kept the Pirates in it even though he struggled with his command. The left-hander surrendered five hits and walked three with five strikeouts in seven innings.
The Reds broke things open with four runs off Pittsburgh reliever Mike Zagurski, a rare hiccup by baseball's best bullpen through the first third of the season as the two rivals moved into a second-place tie behind St. Louis in the NL Central at 34-21.
While Cueto's had his way with Pittsburgh in his 20 career starts, the Pirates have made inroads recently. They spoiled his chance at winning his 20th game in his final start last season and he left a 3-1 loss to the Pirates on April 13 with a strained back that sent him to the disabled list for a month.
He returned with five effective innings in a 4-3 victory over the New York Mets on May 20 then backed it up an even stronger performance six days later against the Chicago Cubs. He exited with a three-run lead the bullpen ultimately gave away in a 5-4 10-inning loss.
This time, Cueto hardly needed the bullpen at all. Keeping the Pirates off-balance with a steady mix of fastballs and sliders, Cueto kept one of baseball's hottest teams in check.
The Pirates managed to get just three balls out of the infield all night, and Inge's single in the fifth was a harmless one-hop single in front of leftfielder Derrick Robinson. The momentum lasted all of one pitch, when Clint Barmeshit into an inning-ending double play.
It would constitute the entirety of any semblance of a rally by the Pirates, who received another quality start from Rodriguez but couldn't finish off their first 20-win month in 21 years.
Rodriguez wasn't quite as sharp as Cueto but was helped early on by a series of long fly balls hit to the deepest parts of PNC Park. The Reds hit four balls to the warning track before Bruce stepped in with one out in the fourth.
Bruce has struggled against Rodriguez throughout his career entering the night just 2 for 32 (.063) against the veteran lefthander. Those numbers inched up when he took a 2-0 fastball and sent it into the first row of seats in right center for his eighth homer of the year.
Phillips followed suit in the sixth, lining a shot that scraped the top of the leftfield wall just over the glove of Pittsburgh's Starling Marte.
That would be more than enough for Cueto, who shaved his career ERA against the Pirates to 2.33.
Cueto's defense helped him out on several occasions. Todd Frazier made a brilliant bare-handed catch-and-throw on a grounder by Marte with one out in the sixth and first baseman Joey Votto speared a liner by Neil Walker two pitches later. Walker held onto his bat then tossed it into air in faux disgust.