The Arsenal left-back also collected the maximum three bonus points to return 18 points in the 4-0 win at The Hawthorns.
His team-mate Alexandre Lacazette (£8.2m) scored twice, taking his tally to four goals in the last three Gameweeks.
They are among five players to earn a place in the Kings of the Gameweek XI for the first time this season.
Joining them are Leandro Trossard (£5.7m), Phil Foden (£6.2m) and Toby Alderweireld (£5.4m).
Manchester City midfielder Foden scored once and supplied an assist in a 3-1 win at Chelsea, while Tottenham Hotspur centre-back Alderweireld netted his first goal of the campaign in a 3-0 victory over Leeds United.
They take their places in a line-up that totalled 135 points in a 3-5-2 formation.