Eyebrows were raised when Jurgen Klopp opted to start Origi ahead of Daniel Sturridge in last Friday's Europa League quarter-final first leg, but the young Belgian rewarded his manager's faith with a crucial away goal at Signal Iduna Park.
And Origi was at it again at Anfield as he bagged a brace playing the second half in place of Sheyi Ojo, who impressed on his first Premier League start.
Klopp made seven changes to his XI with Friday's second leg against his former club in mind, with the recalled Sturridge also offering a timely reminder of his quality with a close-range header that restored Liverpool's lead before the break after Bojan Krkic had equalised Alberto Moreno's early screamer.
It took the buoyant Origi just five minutes to get himself on the scoresheet with Liverpool's third of the game as he nodded James Milner's delivery past Jakob Haugaard, and the 20-year-old's cross-cum-shot added gloss to the scoreline with 25 minutes remaining.
Klopp, who took the opportunity to rest Philippe Coutinho but was able to field Lucas Leiva from the bench after his thigh injury, sees his side climb above Stoke into eighth in the Premier League and can reflect on a job well done ahead of the season-defining visit of Dortmund.
Liverpool enjoyed the better of the opening stages and took the lead in the eighth minute, when two of the four men to keep their places after the trip to Germany combined.
Milner fed Moreno with a quick free-kick after being fouled by Phil Bardsley, and the Spaniard fizzed a dipping long-range drive beyond Jack Butland's deputy Haugaard for his first goal of the season.
But Stoke were level by the midway point of the half when Bojan was allowed the freedom of Liverpool's penalty area to glance home Xherdan Shaqiri's free-kick from the left.
The visitors thought they had turned the game on its head soon after when Peter Crouch headed in a superb cross from Erik Pieters, only for the offside flag to deny the former Reds striker.
And Stoke's frustration was compounded by a moment of brilliance from Liverpool youngster Ojo, who drifted left before dancing his way past Shaqiri and sending an inch-perfect delivery across the face of goal to give Sturridge the easy task of nodding Klopp's team back in front.
Good vibes, 4-1 victory 😎. Congrats on your first start bro @sheyi_ojo beautiful cross for my… https://t.co/AXcQgeKrR2— Daniel Sturridge (@DanielSturridge) April 10, 2016
Origi replaced teenager Ojo at half-time, and the Belgian made an immediate impact after being left all alone to power a close-range header past the helpless Haugaard.
It was one-way traffic after the interval and Origi put the icing on Liverpool's cake when he cut inside Bardsley and angled a ball in towards Sturridge that ended up in Haugaard's far corner.
While also hailing the maturing Origi, Klopp reserved special words of praise for Sturridge, who will hope to have done enough to earn a starting berth for the season-defining visit of Dortmund.
"It's normal after today that you want to speak about Divock, but I actually want to speak about Daniel Sturridge," said the German.
"He worked really hard, scored a brilliant goal, and was so important for us.
we at soccer 60 felicitate with Nigerian born @sheyi_ojo on your first start for liverpool pic.twitter.com/Oq1fSX7VGz— Soccer60 (@soccer60ng) April 10, 2016
"He kept [full Premier League debutant Sheyi] Ojo in the game when he spoke to him on the pitch, and he was really smart in his defending - closing down spaces.
"I'm really happy with him today."
On the impressive Origi, Klopp commented: "You can see what confidence can do. Divock says himself that everything was different when he came here, but he is still a very young player. Expectations were really high because he's a highly-rated striker.
Crazy day.. proud to make my first start for @LFC & assist the big bro @DanielSturridge , still got a lot to learn🙏 #lfc— Sheyi Ojo (@sheyi_ojo) April 10, 2016
"He's had a lot of little injuries, so the most important thing for him is to stay fit. During his last injury he built up his body strength and now everybody can see he has to wear another shirt - he doesn't look like a kid. The first goal - what a cross, what a header, and the second goal is only possible with confidence.
"He really wanted to shoot - it was not a cross - and that was a surprise on the bench, but nice goal! He's in a good way. He's at the start, he has a good base, and now we have to work together."
