In the second Semi-final of the Champions League Twenty20 at Centurion tonight, table-toppers South Australia Red backs take on an impressive Warriors of host nation South Africa.Red backs are the only team in the tournament to win all four of their league matches, while Warriors won their first three encounters before losing to Chennai Super Kings.The Chennai team entered the final last night after beating Royal Challengers Bangalore by 52 runs in a rain-interrupted first semi-final in Durban last night.