A drab encounter at the Britannia Stadium appeared to be drifting towards a goalless draw when Coutinho suddenly found the net with a ferocious 30-yard shot in the 86th minute.
It was the Merseysiders’ only serious effort of the game and, although the contest had opened up more in the second half, the Potters had seemed the more likely to score.
But after Liverpool’s tame surrender at the same ground on the final day of last season, when they were thrashed 6-1, manager Brendan Rodgers may care little about the manner of victory at this stage.
Rodgers is trying to mould together a new side after an extensive summer of recruitment and the much-publicised loss of Raheem Sterling.
He started with six of the players who featured in that Britannia Stadium hammering 77 days previously but handed starts to four summer signings in Christian Benteke, James Milner, Nathaniel Clyne and Joe Gomez.
Stoke, who gave debuts to former Liverpool full-back Glen Johnson, Ibrahim Affelay and Marco van Ginkel, were the more positive side as Liverpool looked disjointed and lacked rhythm.
Even so, an early effort by Mame Biram Diouf did not trouble a shaky-looking Simon Mignolet and a floated Charlie Adam free kick into the box came to nothing.
Adam Lallana had an effort deflected wide for Liverpool but it was not until the 36th minute that Stoke created the first serious openings.
Van Ginkel forced Martin Skrtel to hook a deflected cross off the line and Affelay’s follow-up volley was blocked by Clyne. The rebound fell to Johnson but he scooped over.
A niggly contest became even scrappier as Adam took exception to a Milner challenge and pushed the Liverpool man over and referee Anthony Taylor needed his whistle with increasing frequency.
The game improved slightly after the break with Van Ginkel making Mignolet earn his wages and the hard-working Jordon Ibe skipping into the area only to be denied by a well-timed Marc Muniesa tackle.
Another Adam free kick forced Mignolet into action after running right through the area before Benteke had a shot blocked after a dangerous run by Coutinho. Jack Butland then made his first real save from a Skrtel header.
Stoke made a final push and Skrtel blocked well from Van Ginkel and Diouf headed over from a Johnson cross but Coutinho had the final word. Just moments after he had volleyed over wildly, the little midfielder received the ball from left-back Joe Gomez, turned smartly infield and let fly with a shot from range, dipping the ball over the dive of Butland, who got a finger to the ball but couldn’t prevent it nestling in the net.