PHILADELPHIA -- Zack Wheeler started the week with an epic shutout against the Mets.

It showed why he could be the National League Cy Young Award frontrunner. His dominance Sunday, when the Phillies retired Roy Halladay’s No. 34, completed a sweep and extended the Phillies’ winning streak to eight games, their longest since a nine-game winning streak in 2011. But the Phillies have lost three of four since then, including Friday night’s 6-1 loss to the Reds at Citizens Bank Park.

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The once red-hot Phillies (60-56) fell into a first-place tie with the Braves in the National League East. Atlanta beat Washington on Friday night, while the Mets are a half-game behind both teams following an extra-inning loss to the Dodgers. As wild as it sounds, the Phillies need to win Saturday or Sunday to finish the nine-game homestand with a winning record.

Matt Moore starts Saturday. Aaron Nola starts Sunday.

Wheeler represented the Phillies’ best chance to beat the Reds, but he allowed four runs in six innings.

His line could have been better. Tyler Naquin started the fourth inning with a leadoff single. He hit a chopper to first baseman Brad Miller, who fielded the ball cleanly. But Miller hesitated a moment and Naquin outran him to the bag.

Wheeler then hit Nick Castellanos with a first-pitch sinker to put runners on first and second.

“I honestly didn’t feel good all day,” Wheeler said. “Physically fine, but just a little out of whack. It’s probably the worst I’ve thrown the ball in a really long time. It’s frustrating, but I don’t think that [Naquin hit] really affected me.”

It set up an at-bat against Reds first baseman Joey Votto, who has been the hottest hitter in baseball since the All-Star break, leading baseball in home runs (14), RBIs (32) and slugging percentage (.851) entering Friday. Wheeler struck out Votto swinging on a 1-2 cutter to end the second. But this time, Votto crushed an 0-1 cutter -- the second cutter of the at-bat -- for a three-run homer.

“He saw a few of them,” Wheeler said about his cutter. “I think he saw one or two the first at-bat. As soon as I was about to throw [the 0-1 cutter in the fourth] I was like, whoa, this probably isn’t a good idea of doubling up. Because I think it was a decent pitch. I haven’t gone back and looked at it, but when you throw the sinking pitch in the same place to a guy like him, he’s probably going to make the adjustment pretty quick after he’s already seen it a handful of times.”

Wheeler served up a solo homer to Castellanos in the sixth to make it 4-0. Wheeler entered the game leading all pitchers with a 6.0 WAR, according to Baseball Reference, and leading all NL players with 102 Total Runs, a Baseball Info Solutions metric that looks at a player’s runs created, defensive runs saved and baserunning runs. In other words, Wheeler probably deserves NL MVP consideration, too.

The loss dropped him to 10-7 with a 2.56 ERA.

The Phillies had just five hits -- Didi Gregorius’ two-out double in the ninth scored Jean Segura to avoid a shutout -- so Wheeler could have pitched a gem and still lost. The Phillies have scored just five runs in their last four games. They have hit just .176 with 41 strikeouts and 11 walks in that stretch.

“It’s a little hiccup on the road,” Gregorius said.

Bryce Harper got upset in the ninth with a first-pitch strike call from home plate umpire Ramón De Jesus. The pitch appeared to be just off the outside corner. Harper flied out to center field to finish the at-bat, then said something to De Jesus from the dugout.

De Jesus ejected him.

“There were some calls that he didn’t like, our guys didn’t like,” said manager Joe Girardi, who got ejected on Thursday for arguing balls and strikes. “He just barked. I think it’s a really quick hook. But I think it’s important that people remember that this is going to be a little more of an intense time of year, and I think you’ve got to give players some warning and some leeway.”