ATLANTA -- As the sixth inning unfolded on a hot, sticky Wednesday night, there were signs that Nick Pivetta was nearing the end of the line. Still, the Phillies starter was one pitch away from getting off the field with only a one-run deficit.

If only that pitch hadn't been a hanging slider.

With reliever Juan Nicasio waiting in the bullpen, Pivetta gave up a three-run home run to Atlanta Braves rookie slugger Austin Riley that broke open the game and sent the Phillies to a series-evening 9-2 loss here at SunTrust Park.

“Riley’s pitch just needs to be down maybe an inch,” Pivetta said. “Just an inch and I probably get out of that, but it was a little bit up. It was still off the plate, but he put a good swing on it.”

It was the second homer of the game -- and the ninth in the last four starts -- against Pivetta, and it overshadowed a historic swing for Phillies star Bryce Harper, who became the first player ever to simultaneously record a career milestone hit (his 1,000th) and home run (his 200th) when he took Braves starter Bryse Wilson deep in the top of the sixth.

Harper’s homer instead became a footnote, as the Phillies slid back to 5½ games behind the division-leading Braves, who are on pace to win 94 games. The Phillies must go 49-27 the rest of the way to reach 94 wins.

But never mind the Braves. The Phillies are only a half-game ahead of the third-place Washington Nationals.

“I think as a division at the beginning of the year, we knew it was going to be a juggernaut,” Harper said. “We’ve played some of our worst baseball we can absolutely play in the month of June. To be able to still be in second, only five games I think behind the Braves, I don’t think they’re going to slow down at all and I don’t think the Nats are going to slow down.”

Arm-chair managers will suggest that Gabe Kapler stuck with Pivetta too long, and maybe he did. After all, two of the three batters ahead of Riley -- Freddie Freeman and Nick Markakis -- recorded exit velocities of 100.6 mph and 103.5 mph, respectively, on a one-out single and a sinking line drive that was caught by diving center fielder Scott Kingery.

Two pitches later, Riley hit Pivetta's slider over the center-field fence with an exit velocity of 101.3 mph to stretch a 3-2 lead to 6-2 and finally bring Kapler out of the dugout.

“We had Nicasio ready for Albies. That was the game plan,” Kapler said. “[Pivetta] looked really good against Riley to that point. He was effective up in the zone with his fastball to Riley.”

Besides, when Nicasio entered to face the bottom of the Braves order, he didn’t fare any better. He gave up back-to-back doubles by Ozzie Albies and Tyler Flowers and a two-run homer to pinch-hitting Matt Joyce, three hits that registered exit velocities of 99.9 mph, 109.9 mph, and 99.3 mph.

After the game, Nicasio told the Phillies that he’s been dealing with a tender left groin. Kapler said the veteran reliever would be reevaluated Thursday and might need to go on the disabled list.

The Phillies manhandled Wilson the last time they faced him, scoring four runs on five hits and four walks and knocking him out after only 3⅓ innings on March 30 at Citizens Bank Park.

Seems like eons ago, doesn't it?

This is a different Phillies offense now, one that sorely misses injured leadoff man Andrew McCutchen and is prone to going quiet for too long. And although Wilson is still the same pitcher, he fared much better this time around.

Never mind that Wilson threw mostly fastballs -- 63 of them, to be precise, out of 86 pitches -- he kept the Phillies at bay, allowing little more than Harper's milestone home run. Through five innings, in fact, they had only two hits, both of which were singles.

Wilson completed six innings and allowed two runs on five hits to pick up his first major-league win in only his third career start.