What is the Competition for Season 2002–03, and the Opponent was zenit st. petersburg?
CREATE TABLE "2000s_incorporation" (
  "season" text,
  "competition" text,
  "round" text,
  "opponent" text,
  "series" text
);
SELECT "competition" FROM "2000s_incorporation" WHERE "season"='2002–03' AND "opponent"='zenit st. petersburg';