Third seed Dart, who has recently slipped out of the world’s top 100, fought back to beat Australian teenager Taylah Preston 6-7 (7-9) 6-1 6-2.

Harris, the last British man left in qualifying, needed just 70 minutes to race past Spain’s Carlos Taberner 6-1 6-2.

However, there was disappointment for Watson as she fell 3-6 6-3 6-1 to American Varvara Lepchenko.

Dart will face Japan’s Nao Hibino on Thursday, while Harris, who made his Grand Slam main-draw debut at Wimbledon last year, will play Poland’s Kamil Majchrzak.

Britain’s Francesca Jones will aim to join Dart and Harris in the final round of qualifying when she takes on Switzerland’s Jil Teichmann later on Wednesday.

Players must win three qualifying matches to reach the main draw of the tournament, which begins on Sunday.

Katie Boulter, Emma Raducanu, Sonay Kartal, Jodie Burrage, Jack Draper, Cameron Norrie and Jacob Fearnley all have direct entry into the main singles draw.