In front of a black-clad crowd savoring its first postseason game since 1992, Russell Martin hit two home runs, Marlon Byrd also connected and McCutchen reached base four times.
"We're for real," McCutchen said. "We're definitely for real."
You won't hear the Reds arguing after Liriano continued his mid-career renaissance. The left-hander scattered four hits, struck out five and walked one to win his first playoff game and serve notice the Pirates have no intention of going quietly after spending two decades at the bottom of the standings looking up.
Cincinnati starter Johnny Cueto struggled in his third start since coming off the disabled list last month. Cueto gave up four runs in 3 1-3 innings and appeared rattled by a raucous ballpark that taunted him by chanting his name.
"He couldn't get the ball where he wanted," Reds manager Dusty Baker said. "Usually he can throw that ball through the eye of a needle. Tonight he was up."
The 36-year-old Byrd, acquired by the Pirates in late August from the New York Mets, celebrated the first postseason at-bat of his 12-year career — 1,250 games — by sending Cueto's fastball into the seats to give the Pirates the lead in the second inning. The shot sent another jolt through an already electric crowd, which began singing "Cue-to, Cue-to" in unison when Martin stepped in.
"This is 20 years of waiting. You're seeing it all come out in one night," Martin said. "Hopefully we can keep this atmosphere till late October."
The catcher followed with a drive into the bleachers in left field. The Reds never recovered, ending a 90-win season with a six-game losing streak. Three of those losses came at home against the Pirates in the final series of the season that determined the site of the win-or-die game.