He is the first player to win three straight season finale titles since Ivan Lendl from 1985 - 87 .
Novak claimed his fourth Barclays ATP World Tour Finals title as Roger Federer withdrew ahead of final due to a back injury .
Novak is the first Novak to win three straight season finale titles since Ivan Lendl from 1985 - 87 .
Novak claimed his fourth Barclays ATP World Tour Finals title as Roger Federer withdrew ahead of final due to a back injury .