Manchester City have only conceded three goals so far this season, the best record after 10 games since Chelsea also let three past them at the same point in the 2010-11 season.
Liverpool have been similarly impressive so far, only letting in four, while Chelsea are just slightly behind with seven.
Here, Press Association Sport takes a look at the stars of these solid back lines.
Virgil van Dijk
Many doubted the impact Van Dijk’s arrival could have when he signed for Liverpool in January for £75million and became the world’s most expensive defender, but he has transformed the side’s defensive capabilities.
This season, the Dutch defender has won 38 aerial battles, 10 more than Manchester City’s Aymeric Laporte, according to the Premier League, and has changed a defence which looked capable of conceding every set-piece into a team which has conceded just four goals in 10 games.
Signed from Athletic Bilbao for £57million, Laporte has played 19 games without loss at the centre of Pep Guardiola’s defence despite being largely overlooked last season.
The 24-year-old defender also has the second-highest number of passes of any player, according to the Premier League, with 874 and has played every minute of all 10 games so far this season.
Despite making just 16 starts for Chelsea last season under manager Antonio Conte, the Brazilian defender has played an important role this season, starting in every match so far.
Luiz has made over 200 appearances for Chelsea in his two spells and has impressed this season under new boss Maurizio Sarri, who has spoken about how the defender’s attitude has impressed him.
The young defender could be offered a new contract at Liverpool based on his recent performances, after a knee injury just after signing hindered his start at Anfield.
Gomez looks to have solved the Reds’ defensive question over who would partner Van Dijk, having played nine matches in the Premier League so far this season.
The quality of Manchester City has meant that at times Ederson has been left with little to do, but the Brazilian goalkeeper has made some crucial saves.
Against Tottenham, Ederson made a split-second decision to rush out and deny Harry Kane a goal-scoring chance, and the Brazilian has also impressed with his footwork and passing abilities.