Elevated into the premium price bracket this time around, the Tottenham Hotspur midfielder initially struggled to justify that lofty valuation.
Alli failed to pick up returns in any of the first three Gameweeks and dropped in price from £8.5m to £8.3m by the time he travelled to Stoke City in Gameweek 4.
The South Korea international has registered four goals and two assists over the same period and has been subject to more transfers in than any player in the Gameweek.
There is no doubting Son's form, yet Alli is also stepping up his output and netted the second in England's recent 2-0 win over Malta.
Mauricio Pochettino's recent decision to switch tactics from 4-2-3-1 to 4-1-4-1 looks to have benefitted Alli's FPL points potential.
Over the last four Gameweeks, his touches inside the penalty box (from 2.3 to 4.2), shots per appearance (from 1.3 to 3.2) and efforts in the opposition area (from 0.7 to 1.8) have all improved.
A total of five shots on target over that period is just two less than Son's seven and his tally of 10 key passes is also near-identical to the South Korean's 12.
Dele Alli's recent improvement in FPL
|Goal attempts per match||Penalty box attempts per match||ICT threat per match|
Alli has averaged 2.5 key passes from Gameweek 4 onwards, compared to 0.7 beforehand.
The Baggies have failed to keep a clean sheet in any of their previous four fixtures and conceded twice in two of their three home matches.
Alli then travels to AFC Bournemouth and hosts a Leicester City side who have shipped 10 goals in three away fixtures.
Now down to just 6% ownership, that figure will surely climb should Alli maintain current form and deliver on his promise.
Remember the Gameweek 8 deadline is at 11.30am BST Saturday 15 October