Liverpool secured a vital advantage over Arsenal in the battle for a place in the Premier League's top four with a well-deserved win at Anfield.
Arsenal manager Arsene Wenger gambled by leaving Alexis Sanchez - his leading scorer with 17 Premier League goals - on the bench but the ploy failed miserably as Liverpool took control by the break.
Roberto Firmino's far-post finish put Liverpool ahead after nine minutes and Sadio Mane confirmed their superiority with an emphatic strike just before half-time.
Sanchez, predictably, emerged as a substitute at the start of the second half and set up a goal for Danny Welbeck that gave Arsenal hope but Georginio Wijnaldum struck on the break deep into injury-time to seal Liverpool's win.
Liverpool are now up to third, level with Manchester City on 52 points - but Arsenal are now in fifth trailing that pair by two points.
Wenger pays for Sanchez blunder
Arsenal and Arsene Wenger had so much riding on this game - a meeting where they knew defeat would leave them outside the Premier League's top four.
It made his decision to leave his most dangerous attacker Sanchez on the bench totally inexplicable, Wenger's tactical ploy backfiring badly as Liverpool assumed control in those crucial first 45 minutes.
Brave or desperate? Or a touch of both? Either way it was consigned to the dustbin at the interval.
Wenger preferred the physicality and aerial threat of Olivier Giroud and Danny Welbeck but Arsenal's failure to arrive in any attacking positions in the first half totally negated any impact he hoped they would have.
The folly of Wenger's selection was further exposed by the manner in which Sanchez transformed Arsenal's approach when he emerged as a substitute, setting up Welbeck's goal - although the Chilean's energy levels dried up as the half went on.
Wenger's decisions will come under the closest scrutiny as speculation continues about his future, and if Arsenal miss out on the Champions League failed moves like this will understandably be portrayed in an unflattering light.
Sanchez's demeanour at the final whistle told the tale. As Liverpool manager Jurgen Klopp celebrated with his backroom team, he offered the briefest of gestures to Arsenal's fans before going straight down the tunnel.
Klopp masters rivals againLiverpool are unbeaten against the top six tin the Premier League this season
Liverpool have faltered badly against the Premier League's strugglers, losing and performing dismally in defeat at Hull City and Leicester City - who were both in the bottom three when those games kicked off.
Klopp, however, has mastered the art of overcoming Liverpool's closest rivals and this may yet be the key to achieving the top four place that was the goal before the start of the season.
Klopp's record against Arsenal, Chelsea, Manchester City, Manchester United and Tottenham is highly impressive and this victory leaves with seven wins, eight draws and one defeat from 16 league games.
This was not a vintage Liverpool performance but the energy and creation shown here was in stark contrast to that shown at the King Power Stadium on Monday and more akin to the recent 2-0 win against Spurs here at Anfield.
Liverpool were helped by Philippe Coutinho's best display since he returned from a seven-week absence with an ankle injury while Ragnar Klavan offered a more physical defensive presence than Lucas, dropped after the Leicester debacle.
This result keeps Liverpool in the shake-up for a Champions League place - but also underscores why they have collapsed in the title race.
Results against your closest rivals, while desirable, are not enough on their own.
Wijnaldum the man for the big occasion
Quietly and without fuss, Wijnaldum is having a fine impact at Liverpool in his first season since his £25m move from Newcastle United.
He operates in the shadow of more eye-catching players such as Coutinho, Adam Lallana and Firmino, but he is missed when he is not playing and contributes vital goals when he does.
Wijnaldum scored the winner against Manchester City, the equaliser against Chelsea and the vital third goal here. The man for the big occasion.