The Reds right-hander induced 10 groundouts and was cruising along at 61 pitches. But then the rain came, and Leake's five-hit, three-run outing was finished.
He earned his third no-decision of the season against the Cubs, who went on to win in walk-off fashion, 4-3.
"Shutouts are a rarity, and he battled tonight," said Reds manager Bryan Price. "I looked at his pitch count and thought, 'Shoot, there's no reason why he might not pitch a complete game.' I wasn't feeling like they were on him. I thought he did a pretty nice job of doing his damage control."
Leake was on pace for his fourth straight quality start before the rain interruption of 2 hours, 48 minutes. Working through the Cubs' aggressive approach at the plate, he had only one strikeout and didn't walk a batter as Chicago swung on nearly every first pitch against him.
"I was mainly in a low pitch count because of them," Leake said. "They were swinging early in the count. It was do or die in the first couple of pitches because they were so aggressive tonight."
Leake was burned in the second inning on Chicago's aggressive approach, as Kris Bryant singled to left field on the first pitch he saw before Miguel Montero homered to center field on the second pitch.
"They were both mistakes that they did what they should have done with," Leake said. "They made me pay."
Leake now carries a 4.35 ERA after the short outing, but he has posted a 3.32 ERA in the month of June after he finished May with a 6.75 ERA. Still, he was quiet and subdued in the clubhouse after the game for someone who had been able to do what he does best.
"In those games, those are like eight-inning, four-run type games, and it was leading that direction," Leake said. "But sometimes the rain gets in the way."