UPDATE 1-Golf-Gay leads the way at stormy Memphis

* Gay leads by two shots as storms end play early

* More than half the field must complete round on Saturday

* Molder and Australian Allenby tied for second

(Updates after play ended early)

MEMPHIS, June 12 (Reuters) - American Brian Gay shot a four under-par 66 to lead by two shots on 10-under overall in the second round of the St Jude Classic on Friday.

Stormy weather ended play early at TPC Southwind and over half the field need to complete the round early on Saturday.

Gay, the overnight leader after an opening six-under 64, continued his impressive showing with a string of five birdies in the first eight holes.

Although he finished with bogeys on the par four 17th and 18th, Gay still has the advantage over compatriot Bryce Molder and Australian Robert Allenby on eight-under.

But Allenby only managed to complete 15 holes before a premature end to the day's play with thunder clouds closing in.