In Tennis, world number one Novak Djokovic and second seed Angelique Kerber have stormed into the semi-finals of the US Open, the final Grand Slam of the season. Djokovic progressed after Frenchman Jo-Wilfried Tsonga retired due to a knee injury when the scoreline was 6-3, 6-2 in the Serb's favour. France's Gael Monfils also entered the last-4 as he defeated compatriot Lucas Pouille, 6-4, 6-3, 6-3. Pouille had stunned Rafael Nadal in the pre-quarterfinals.In Women's Singles, Angelique Kerber secured a semi-final berth beating Italian Roberta Vinci, 7-5, 6-0. Caroline Wozniacki also made it to the semis with a 6-0, 6-2 win over Anastasija Sevastova of Latvia.World number one Serena Williams, Briton Andy Murray and Stanislas Wawrinka will be seen in action in the quarterfinals today.Meanwhile, India's campaign in the tournament came to an end after Sania Mirza and her Czech team-mate Barbora Strycova made an exit in the Women's Doubles quarterfinals. The pair, placed seventh, lost to the top seeded French team of Caroline Garcia and Kristina Mladenovic, 6-7, 1-6.