The visitors, overseen by former Liverpool Under-23 boss Neil Critchley, were the better team in the first half and went two goals up courtesy of CJ Hamilton and Jerry Yates.
Liverpool, who were without their European internationals, did manage to reduce the arrears before the break thanks to the returning Joel Matip.
Story of the game
Blackpool looked the more dangerous side from the off, and should really have been ahead inside two minutes. Hamilton got in behind down the right and saw Yates totally unmarked in the middle, but the cross bounced beyond him.
There was no such charity on 15 minutes when 17-year-old Billy Koumetio was unable to gather an overhit Mohamed Salah pass and Hamilton pounced, running through and firing the ball into the bottom right corner with conviction.
Minamino had twice gone close for Liverpool but Blackpool continued to enjoy plenty of space on the counter.
And they made the most of it just after the half-hour mark when Hamilton beat Alisson to the ball on the right edge of the area and went down after a clear trip from the Liverpool goalkeeper.
Yates stepped up to the take penalty and clinically dispatched it into the left-hand corner, evading Alisson's reach.
Liverpool then began to play with greater urgency in the closing stages of the half.
It could even have been level pegging going in at the break, but Keshi Anderson thwarted Firmino's efforts to set-up Mane for a tap-in following Salah's through ball.
Liverpool promptly took charge when the game resumed.
The visitors were hemmed-in but the circumstances of the equaliser were admittedly unfortunate. A frantic clearance six yards from goal was hit straight at Mane, forcing a reaction save from the goalkeeper before the Senegalese international bundled the ball home at the second attempt.
Liverpool grabbed the lead just two minutes later, with Minamino teeing-up a close-range Firmino backheel following Ki-Jana Hoever's cut-back from the byline.
Milner's stumble on the edge of his own box nearly let the visitors back in, but Yates' stretching effort deflected wide off substitute Nathaniel Phillips.
Liverpool introduced Origi and Elliott on the hour and it wasn't long before the pair combined to engineer Liverpool's fourth goal via a Firmino dummy. Elliott strode onto the Belgian's through ball and his shot proved too powerful for Blackpool's second-half keeper Jack Sims.
The Reds were in an irresistible stride and struck again moments later, Firmino receiving Curtis Jones' neat pass and returning the favour for Minamino, who confidently steered the ball in at the near-post.
There was no let-up in the pressure, and five minutes from the end the winning margin inflated further. Elliott shuffled the ball out to the elusive Jones, whose low cross left Origi with an easy finish.
And there was still time for a seventh, with Van den Berg the unlikely source. A corner was worked to Keita, he crossed, Elliott played it back across goal and the Dutch centre-half converted.
Minamino impressive in new role
It's all-too-easy to draw hasty conclusions from these friendlies, but it's clear that Takumi Minamino is in good shape.
Off the back of his duck-breaking goal in the Community Shield, Minamino played the full 90 here, this time lining-up in an attacking midfield slot behind Roberto Firmino.
And he was probably the Reds' man of the match, instrumental in the turnaround by virtue of his encouraging link-up play.
Firmino and Minamino, who combined for two of the goals, could give defenders real headaches as rotating false 9s.
The January arrival is certainly in contention to start Liverpool's season-opener against Leeds United next Saturday.