Sadio Mane and Mohamed Salah were also on the mark.
Here is what the media made of the victory...
Melissa Reddy, ESPN
In the aftermath of Liverpool's 2018 Champions League defeat to Real Madrid in Kiev, manager Jürgen Klopp was in his Formby home when he picked up a framed photograph of Alex Oxlade-Chamberlain. The midfielder, who was crucial to the club reaching European football's showpiece, had suffered damage to multiple knee ligaments a month earlier. Klopp held the image up, telling assistant manager Peter Krawietz as well as a friend - "Die Toten Hosen" lead singer Campino - and a German journalist of his sadness at the English midfielder's injury situation. He felt as though "Ox" had sacrificed his body to get Liverpool so far, only to be robbed of the chance to affect matters at the most pivotal juncture. As the squad clapped their supporters at the NSC Olimpiyskiy Stadium following Real's 3-1 victory, Klopp had to compose himself when he saw the player, on crutches, crying into his palms. On Wednesday night, however, the scenes were markedly different. On his first Champions League start in a year and six months, Oxlade-Chamberlain scored two absolute stunners - the second worthy of being watched on loop for hours - as Liverpool eased past Racing Genk 4-1 in Belgium. It has been a long, challenging and mentally draining journey for the former Arsenal man to manoeuvre. Oxlade-Chamberlain has endured a long spell out and a gruelling rehabilitation schedule, all the while obsessing about getting back to his very best and forcing his way from Liverpool's fringes to the forefront of their midfield thinking. The 26-year-old even ceded time off during the international breaks to fit in extra sessions and ensure he is in peak physical condition. His progressive play helped the Reds seal the equaliser at Manchester United on Sunday, and it was his double that switched a tricky contest in Genk to a platform for his side to showcase an attacking masterclass. Alongside him, Naby Keita - who has also battled back from troublesome injuries - made his first Champions League start and was at the heart of Liverpool's progressive play. He made a game-high 118 passes (80 in the opposition half) and still managed to complete 93 percent of them. The Guinea international had the most touches (138), contested the most duels (14), made the most possession gains (12) and added three tackles and an interception. That was no surprise to insiders at Melwood, who told ESPN FC that he looked "ready to catch fire" during recent training sessions in which he was the standout performer.
Neil Jones, Goal.com
It was exactly the kind of night Oxlade-Chamberlain had waited for. A European tie, that blood-red Liverpool strip. A first Champions League start in 18 months. A goal inside two minutes, and a stunner to wrap the game up in the second half. That’s how to influence a game of football. Oxlade-Chamberlain’s exquisite double set the Reds on their way to a 4-1 victory in Genk – a result which, coupled with Salzburg’s defeat to Napoli in Austria, puts Klopp’s men in a strong position to qualify from Group E. Oxlade-Chamberlain didn’t take long to register his first competitive goal since April 2018, a smart, skimming effort inside goalkeeper Gaetan Coucke’s right-hand post from 20 yards, after a line-breaking pass from birthday boy Fabinho. One minute and 50 seconds was the official time, making it the fourth-fastest goal Liverpool have scored in this competition. A great moment, but the best was still to come. Twelve minutes after half time, Roberto Firmino laid the ball back to Oxlade-Chamberlain, again 20 yards from goal. And as two Genk defenders converged, he produced an outrageous, first-time strike with the outside of his right foot, the ball curling beyond Coucke and in via the underside of the crossbar. The smile on his face said everything. It was the first time he had scored twice in a game since October 2016, when he was playing for Arsenal against Reading in a League Cup tie. He won’t have scored many better. And, just like Adam Lallana at Old Trafford on Sunday, he’d produced a big contribution after spending so long in the shadows.
Paul Gorst, Liverpool Echo
Klopp excited plenty of supporters with his bold team selection of Oxlade-Chamberlain and Keita in his midfield three with enforcer Fabinho mopping up the problems on his 26th birthday. For both Oxlade-Chamberlain and Keita, this represented a real chance to grasp the nettle and show their manager how big a role they can play in this season's festivities and both appeared to have a point to prove. It was Oxlade-Chamberlain who struck first, rattling a daisy cutter into the bottom corner inside two minutes to begin the new chapter of his Champions League story in Liverpool red. It was this competition that brought his buccaneering form - arguably the best of his career - to a shuddering halt in April 2018. Thankfully, that dark time is a distant memory for Oxlade-Chamberlain who reignited his Liverpool lifespan with two brilliant strikes that lit up the Luminus Arena. Now, hopefully, these goals, performance and victory as a whole has given new direction to his fortunes in Europe's biggest club tournament. The same can apply for Keita, who was making his first start in the Champions League since pulling out of the semi-final in Barcelona on May 1. Injury-free and back in the Liverpool team, both Keita and Oxlade-Chamberlain can build on their exertions here.
David Lynch, Evening Standard
Not since suffering a terrible knee injury against AS Roma 18 months ago had Alex Oxlade-Chamberlain started a Champions League game for Liverpool. And the two-goal performance that followed certainly wasn’t a bad way for the Englishman to announce his return to Europe’s biggest stage. It is often forgotten just how key to the Reds’ midfield Oxlade-Chamberlain had made himself before his lengthy absence from first-team involvement. But tonight’s showing is a reminder that he is arguably the club’s biggest goal threat outside of that venerated front three. And he will have earned plenty of chances to prove that in the near future with his efforts against Genk.
Andy Hunter, Guardian
Klopp rewarded both Oxlade-Chamberlain and Keita for their influential substitute displays against Manchester United on Sunday with starting roles here. The England international needed all of 111 seconds to repay his manager with the opening goal. His first goal since the Champions League quarter-final first leg defeat of Manchester City in April 2018 followed a poor defensive clearance from the home side. Andy Robertson and Roberto Firmino reacted sharply to keep the pressure on and Oxlade-Chamberlain, given time to pick his spot from almost 25 yards, found the bottom corner with precision. The visitors largely nullified Genk’s threat in the second half and were given the comfort of a two-goal lead when Oxlade-Chamberlain beat Coucke with a magnificent finish. Keïta, an increasingly creative presence in midfield, found Firmino inside the area with a measured chip. The Brazil forward laid the ball back out to the waiting midfielder who clipped it first time over the Genk keeper and in off the underside of the bar. Oxlade-Chamberlain was side-on to goal when he connected. It was the goal of a confident player, a reward for perseverance through horrendous injury, and he departed to a standing ovation from the Liverpool section when replaced by Georginio Wijnaldum.
This story has been reproduced from the media. It does not necessarily represent the position of Liverpool Football Club.