Manchester City and Liverpool's ascension to the two top dogs in the Premier League has seen every meeting in recent seasons met with increasing animosity, ahead of Sunday's latest battle for supremacy.
No player bears the brunt of that bad blood more than Raheem Sterling on his return to Anfield.
Sterling shot to fame as a teenager in the 2013/14 season as a rollercoaster ride took Liverpool agonisingly close to ending their long wait to win a league title.
Two years later, he left in acrimonious circumstances with Liverpool going backwards on the field and disputes over his contract off it.
Four-and-a-half years on, there is no doubt who got the better end of the ?50 million deal that took him to City.
Sterling has flourished under Pep Guardiola, becoming a vital part of City's two title-winning campaigns in the last two seasons, while Liverpool's wait for a league crown has now stretched to 30 years.
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The England international is one of many tales of what might have been for Liverpool over the past three decades, but is also symbolic of how times have changed at Anfield.
Sterling left just three months before Jurgen Klopp arrived to revitalise the Reds after a season in which they finished sixth, 17 points behind City.
Liverpool have still yet to finish above the English champions in Klopp's four seasons in charge, but the gap was down to a single point as City edged a titanic title race last season.
- 'All the credit' for Sterling -
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"His physicality is incredible. He's strong the day after the game, he could play another game. He can play on both sides, is fast, defensively help us a lot, so is an extraordinary player."
"Just now it's about consistency but he has shown in the last 12 to 18 months that he is able to be that consistent. He is among the five best attacking players in the world, definitely."