NEW YORK - Top-seeded Novak Djokovic past Italy's Matteo Berrettini, 5-7, 6-2, 6-2, 6-3 to advance to the men's singles semifinals in the US Open here on Wednesday.

"When I lost the first set, I managed to forget about it, kind of be in the moment. I was dialed in, locked in from the beginning of the second set. I put my tennis to a different level. It's been the best three sets I've played in the tournament so far, for sure," Djokovic said.

The 34-year-old Serbian recovered from a slow start before he won the rest of the game.

"It was a great match. A lot of energy on the court, off the court as well," Djokovic said, "Matteo is a terrific player, an established Top 10 player. Every time we face each other, it's always a close battle. It wasn't any different tonight."

The world No.1 now just needs two wins to complete the calendar-year Grand Slam, a feat that hasn't been accomplished in men's tennis in more than half a century. Australian Rod Laver was the last man to sweep all four majors in a single season (1969).