Littler threatened to overturn an early deficit but Humphries held his nerve to win the last three legs.
Fifth place was enough to guarantee the Dutchman a fourth straight crown.
The estimated number of entries and exits at Liverpool Street in the year to the end of March was 94.5 million.
The McLaren driver trails Max Verstappen by 62 points heading into the final three rounds of the championship.
The world number one defeated Taylor Fritz 6-4 6-4 to become the first Italian champion.
The world number three joins Spanish great Seve Ballesteros in second place in the all-time list with six order of merit triumphs.
The world number one will bid for another big title against first-time finalist Fritz.
Gabriel Martinelli broke the deadlock with a clever near-post finish in the 60th minute before Pedro Neto’s equaliser earned a point for Chelsea.
The Reds capitalised on Manchester City’s defeat at Brighton with a 2-0 win over Aston Villa.
The Chinese star held off Chris Wakelin 10-7 in Nanjing.
Norris is 62 points behind Verstappen with only 86 points available.
The Dutchman claimed a remarkable win that edges him ever closer to a fourth consecutive title.
The Sweden international converted Anthony Gordon’s inviting 12th-minute cross with aplomb.
Norris will start Saturday’s sprint race at the Brazilian Grand Prix from second, two places ahead of Verstappen.
Norris looked set to land top spot only to be gazumped by Piastri with the Australian’s final throw of the dice.
