In 2013, he qualified in Auckland and beat Dutch no.
1 Robin Haase in the first round, only to fall to Tommy Haas in the second.
He also reached the second round in Zagreb.
At the Australian Open, he teamed with Robin Haase to reach the doubles final, losing to the Bryan brothers.
In Rotterdam, Sijsling beat Jo-Wilfried Tsonga in the first round for his first top-10 victory.
At Wimbledon, Sijsling had his best showing in the singles tournament of a Grand Slam event by reaching the third round, beating seeded player Grigor Dimitrov in the process.
In 2013, he qualified in Auckland and beat Dutch no. 1 Robin Haase in the first round, only to fall to Tommy Haas in the second. He also reached the second round in Zagreb. At the Australian Open, he teamed with Robin Haase to reach the doubles final, losing to the Bryan brothers. In Rotterdam, Sijsling beat Jo-Wilfried Tsonga in the first round for his first top-10 victory. At Wimbledon, Sijsling had his best showing in the singles tournament of a Grand Slam event by reaching the third round, beating seeded player Grigor Dimitrov in the process.
Igor Sijsling