But when Lester lined a curveball for a two-out single in the fourth inning with the Phillies trailing only by two runs, Hellickson's inability to execute opened the floodgates to a four-run frame -- capped by a three-run homer by Kyle Schwarber -- and, ultimately, to an 8-3 loss on Tuesday night at Wrigley Field.
"It's as about as frustrating as it gets," said Hellickson, who took his first loss of the season after giving up six runs and three home runs in four innings. "Nobody on, two outs with the pitcher up, 1-2 count. It doesn't get much more frustrating than that."
Not much had gone wrong for Hellickson -- the first Phillies pitcher since Roy Halladay in 2010 to begin a season with four straight victories -- until Tuesday.
But after leaving a changeup up in the strike zone to Cubs slugger Kris Bryant in the first inning, resulting in a homer, and then surrendering another solo shot to Javier Baez in the third, it was clear Hellickson was off his game.
Hellickson hadn't allowed more than two earned runs in an outing this season, but that changed against the Cubs when he fell behind too many hitters on too many occasions. He ended up allowing eight hits and walking two over four innings, in addition to surrendering the three home runs.
"He was a little off," manager Pete Mackanin said.
But even after leaving pitches up to Bryant and Baez, Hellickson still had a chance to minimize the damage. After getting Jason Heyward and Willson Contreras to ground out to start the fourth inning, Hellickson quickly jumped ahead of Lester.
But just when it appeared he would be able to keep the Phillies' deficit at two runs, Lester and Baez each singled, which brought up Schwarber.
One swing later, the Phillies trailed, 6-2.
"Just a lack of execution," Mackanin said. "They're not robots, and they make mistakes, and unfortunately, it cost us."
But it all started with losing Lester with two outs and nobody on. Lester contemplated not swinging at a curveball before Cubs hitting coach Eric Hinske asked the worst thing that could happen if he did.
"I saw [the curve] and swung at it this time for whatever reason and was able to put the barrel to the ball and get a base hit," Lester said. "I'm just up there trying not to look too much like an idiot and not get hurt."
No one was more bothered by the single than Hellickson, who struggled to come up with answers for his first poor outing of the season.
"I fell behind too many guys," he said. "When I did get ahead, they fouled some good pitches off [and] got back into some hitters' counts. I wasn't able to put away guys.
"I didn't really have command of much. The more pitches I threw, the worse it got."
Jeff Arnold is a contributor to MLB.com based in Chicago and covered the Phillies on Monday.