New York: Novak Djokovic swept into the last 16 of a Grand Slam tournament for the 26th successive time Friday and celebrated the victory with a spot of baby-sitting.
The world number one defeated Italy`s Andreas Seppi for the 11th time in 11 meetings, 6-3, 7-5, 7-5 to inch closer to a sixth final in New York.
But instead of celebrating, the 28-year-old rushed straight into his media obligations before heading back to his city base to join wife Jelena and baby son Stefan.
The couple`s first child was born last October and since then Djokovic has won 69 matches and eight titles with just five losses.
That run includes this year`s Australian Open and Wimbledon crowns.
"I think it`s a great balance. I`m experiencing it now since last October," said Djokovic of his professional and private lives.
"It has brought a lot of joy in my life, but also a lot of positive energy and motivation to my professional life."
Djokovic, whose Grand Slam collection now stands at nine, is aiming to reach the finals of all four majors in the same year for the first time.
Only a heartbreaking loss in the French Open final to Stan Wawrinka in June prevented him from a shot at a calendar Grand Slam -- a feat not achieved by a man since Rod Laver swept all four in 1969.
"You always try to set up a new kind of goals, find an inspiration," he added.
"You`re always in a pursuit of finding that something that is going to drive you, that is going to keep you on alert every single day, keep you going for practice sessions, and doing the same things day in and day out.
"When my boy arrived, it was completely a new dimension of experience for me and my wife.
"I`m still riding the wave. It has helped my tennis, definitely. I`m more focused, but I`m balanced. You need that balance. Tennis is a very demanding sport. You need something that is going to keep you intact."
The family factor has also proved crucial to Djokovic`s rivals.
World number two Roger Federer is the father of two sets of twins.
Andy Murray, meanwhile, the world number three, is set to become a father in February while Wawrinka has a five-year-old daughter.
"Family -- what bigger inspiration can you find more than that?" asked Djokovic.
On Friday, Djokovic recorded his 31st successive win over Italian opponents with his win over Seppi.
He will next face Spanish 23rd seed Roberto Bautista Agut on Sunday for a place in the quarter-finals.
The Serb star had dropped just 10 games in his first two rounds, not facing a break point, but was pushed hard by 25th seed Seppi, who knocked Federer out of the Australian Open.
He dropped serve for the first time in the second set and was broken again as he served for the match in the 10th game of the third.
But the 31-year-old Seppi was unable to capitalise and handed the advantage straight back to the world number one in the 11th game.
"I had to hang in there and try and play at my pace," said Djokovic.
"He was aggressive and went for backhands down the line. I just had to stay patient and wait for my opportunities, which is easier said than done."
Djokovic ended with 11 aces and 37 winners but will look to reduce the error count of 31 in the fourth round, where victory would put him into a 25th consecutive Grand Slam quarter-final.