PITTSBURGH (AP) -Two batters faced, two runners on. Bronson Arroyo hadn't gotten an out yet, but he realized he already was at a key point in the game. Turns out the Pittsburgh Pirates were, too.

Arroyo bounced back from his worst start of the season to limit Pittsburgh to four singles over eight innings, a slumping Brandon Phillips homered and the Cincinnati Reds ran the Pirates' scoreless innings streak to 22 with a 4-0 victory Friday night.

Arroyo (4-1) and reliever Francisco Cordero combined to give up five hits, none for extra bases, in the Reds' fourth shutout victory of the season and second in as many games. Edinson Volquez allowed a lone hit over eight innings in beating Houston 3-0 on Wednesday.

''When things are going good and the pitching staff feels good, you definitely want to continue that,'' Arroyo said. ''I feel like this is definitely the best staff we've had since I've been here. If we can continue to do things like this, it breeds confidence in the guys from top to bottom.''

The Pirates were shut out for the second straight game, following up a 1-0 loss Wednesday in which Milwaukee winning pitcher Yovani Gallardo homered for the only run. They haven't scored since the fifth inning of a 6-5 loss to the Brewers on Tuesday.

''It's one of those things where we're snake bitten with the bats, but it's a long season and the bats will start waking up,'' said Nyjer Morgan , who had two of the five hits. ''We're not distressed about it, it's part of the game you go through.''

Arroyo (4-1) allowed eight or more hits in three of his first four starts and was coming off a 10-2 loss to Atlanta on Saturday in which he gave up nine runs and nine hits in 5 2-3 innings, jumping his ERA to 6.48.

The right-hander started off by giving up singles to Morgan and Freddy Sanchez , but got Nate McLouth to ground into one of the two double plays the Reds turned with Arroyo on the mound. McLouth had been out for a week with a rib cage injury. After that, Arroyo didn't permit another hit until the seventh while outpitching Pirates starter Zach Duke (3-2).

''I knew my command was good, and it was like, 'If I can make it through this inning without giving up a run, I'll be all right,' '' Arroyo said. ''Luckily I got the double play and got out of the inning and it worked out the way I thought it would. And it doesn't always happen that way.''

The Pirates put the leadoff man on base five times, but never again had multiple runners against Arroyo.

The Reds finally got to Duke on Willy Taveras ' double and Joey Votto 's run-scoring single in the sixth. Phillips, his average down to .180, hit reliever John Grabow 's first pitch of the eighth inning into the right-field seats for his third homer to make it 2-0.

''I felt good out there, had good command, I just got outpitched a little bit - Bronson was really good,'' said Duke, who reduced his ERA to 2.21 despite losing. ''When you're in a game like that, one mistake can hurt you, and I was the one who made a mistake. I missed a spot on Taveras and left the ball over the plate.''

Arroyo, released by the Pirates after the 2002 season, struck out four and walked three while lasting more than seven innings for the first time this season. He had given up at least one run in 19 consecutive starts since July 4.

''He was hitting those corners, getting those calls and everything,'' said Morgan, who apparently felt home plate umpire Mike DiMuro had a wide strike zone. ''It's kind of a little bit tough when the pitchers are getting those calls, but he kept us off balance.''

Notes: Cordero finished up in a non-save situation because he was throwing in the bullpen when the Reds scored twice in the ninth. ... Despite an umbrella giveaway on a night it rained intermittently the final three innings, the crowd was only 14,238. ... The Reds are 8-3 on the road. ... The Pirates have lost five of seven to drop back to .500 at 11-11. They were a season-high four games over .500 on Sunday.