Half of the lineup for the Friends Life t20 Finals Day has been confirmed following Surrey and Northamptonshire's victories over Somerset and Durham respectively on Monday.

Both teams took advantage of securing home quarter-finals to book their place for the 10th edition of the spectacle, which will take place at Edgbaston on August 17.

Surrey, the inaugural winners of the competition in 2003, chased down Somerset's total of 148-6, which was posted largely thanks to an unbeaten 70 from England wicketkeeper-batsman Craig Kieswetter.

Each of the Lions' top three, Jason Roy (28), Stephen Davies (35) and Vikram Solanki (38) made important contributions as they reached their target with three wickets and more than an over to spare.

Big hitting from Australian Cameron White, who smashed four sixes in a 32-ball knock of 58, fired Northants to 183-4 after opening pair Kyle Coetzer (44) and David Willey (46) put on a useful 89 for the first wicket.

Durham struggled to get going in the early stages of their reply, and they eventually finished 36 runs short despite a quick-fire 51 not out from international prospect Ben Stokes.

Reigning champions Hampshire take on Lancashire on Wednesday, while Essex visit Nottinghamshire on Thursday in the competition's other last-eight matches.