Clayton squeezed through a tough group to become the first Channel Islander ever to qualify for the main knock-out draw while Lamb, the youngest competitor in her group, placed third to progress to the Consolation event.
With only two to qualify from his group, Clayton tied for second place with two other players.
However, the Millfield School student progressed with the highest percentage having won his opening match in two-straight sets whereas his challengers both won matches on a tie-break.
Clayton defeated Ben Blackwell (7.2) 6-3, 6-1 while he was defeated by Alistair Kwan (8.1) 6-3, 2-6, 9-11 and Jonathan Davies (6.2) 6-2, 7-5.
Lamb, who will now be one of the top seeded players in the Consolation draw, beat her first opponent 6-3, 6-1 before losing yesterday against two seeded players.
