Chelsea face title rivals Manchester City in their next league game on Sunday, 11 October
Holders Chelsea began their defence of the Women's Continental League Cup with a 4-1 win over rivals Arsenal in a repeat of last season's final.
Guro Reiten netted twice for Chelsea after Magdalena Eriksson's opener was cancelled out by Caitlin Foord, and Beth England added a late fourth.
Championship Liverpool beat Manchester United 3-1 in Wednesday's main upset.
Manchester City came from behind to beat in-form Everton 3-1 in a pre-cursor to 1 November's FA Cup final.
There were also first wins of the season in all competitions for Women's Super League sides Aston Villa, Birmingham City, Bristol City and Tottenham, all against second-tier opposition, while Reading earned a third straight win as they beat Charlton 4-0.
Top-flight sides Brighton and West Ham drew 2-2 in 90 minutes but the Hammers picked up an extra point for winning the subsequent shootout, while Championship clubs Durham and Crystal Palace also enjoyed victories in Wednesday's opening round of group-stage games.
The winners of the six round-robin groups will all progress to the quarter-finals, along with the two best runners-up.
Group stage results - Wednesday's opening fixtures
Group A
Aston Villa 1-0 Sheffield United
Durham 5-2 Coventry United
Group B
Chelsea 4-1 Arsenal
Tottenham 4-0 London City Lionesses
Group C
Liverpool 3-1 Manchester United
Manchester City 3-1 Everton
Group D
Brighton 2-2 West Ham (2-4 pens)
Reading 4-0 Charlton
Group E
Blackburn 0-1 Birmingham
Leicester City had no fixture in this round of games, as Group E has three teams
Group F
Bristol City 4-0 London Bees
Lewes 1-2 Crystal Palace
