Column: Novak Djokovic takes next step at U.S. Open with win over Andy Murray

Two tennis pit bulls sank their teeth into each other on a warm and windless night at the U.S. Open on Wednesday.

It was Novak Djokovic versus Andy Murray. Talk about strong teeth.

Right now, with Rafael Nadal out with an injury, all they needed to make this a showcase of the game’s best of the best was Roger Federer in the umpire’s chair.

When a couple of Murray’s molars started to give way just a bit in the third set — and his back stiffened in the fourth — it opened the door for Djokovic to pull away to a 7-6 (1), 6-7 (1), 6-2, 6-4 victory.

Even with the anticlimactic ending, the tennis stayed on a high level throughout and it would be hard to find a person in the 23,000-seat Arthur Ashe Stadium who felt deprived of their money’s worth. If you had a ticket to this one, it was a golden one.

At 12:30 a.m. Eastern time, on a school night, there were still about 15,000 people in the stands. From the start, the fancy suites had been overflowing with people, as well as expensive liquids.

The match ended at 1:15, and took 3 1/2 hours.

It was a perfect night for this. And expectations were off the charts. In the end, expectations were met.

At one point, after an especially competitive baseline exchange — huge backhands and forehands, slice to slice, topspin angles and changed pace from both players that went on for perhaps 30 strokes — Djokovic gestured to the fans to whoop it up, show some appreciation. He didn’t need to. They had all night, on just about every point.

There are four unbelievably great men’s players in the tennis world right now, the aforementioned, and it doesn’t get much better than a matchup at night in the U.S Open of two of them. Coming in, Djokovic and Murray had played 20 times and Djokovic had won 12.

More significant, Murray’s last two wins over the slashing Serb were in Grand Slam finals — the never-to-be-forgotten Wimbledon win last year by Scotland’s favorite son that ended the Brits’ 77-year drought in men’s singles at its most cherished sports event. Then there was the 2012 final here.

Those are Murray’s two Grand Slam victories. Djokovic has seven, including the most recent Wimbledon title.

Murray’s victory over Djokovic in the 2012 U.S. Open final went five sets. This one felt like it would too. As a matter of fact, after the first two sets, it looked as if the John Isner-Nicolas Mahut long-match record at Wimbledon, where they don’t play tiebreakers in the deciding set, might be in danger.

First set. Tiebreaker. Djokovic dominates and wins when Murray can’t return a 121-mph serve.

Second set. Tiebreaker. Murray dominates and wins when Djokovic keeps hitting shots into the net, including the last one on set point.

When Murray floated a backhand long for a service break and a 3-1 Djokovic lead in the third set, the match was 2:30 old and British sportswriters were pondering a pool on whether the match would end before the sun came up in London.

An unusual aspect about the match was that it was a quarterfinal. In their 20 previous matches, they had played that early in a tournament only three times. This time, it happened because Murray has struggled of late, recovered slowly from back surgery late last year, and slipped to No.10 in the rankings for a while. He was seeded No. 8 here and on the side of the bracket with No. 1 Djokovic.

Late in the final set, Murray asked for a heat pack for his back. Soon, Djokovic had administered the final treatment — getting him off the court.

On match point, a now-hobbling Murray netted a shot and Djokovic had made his eighth consecutive U.S. Open semifinal.

In the semifinals, he will play Japan’s Kei Nishikori, who followed his 4 1/2-hour match Monday night that went into Tuesday with another five-set marathon victory Wednesday, this one over No. 3 Stan Wawrinka of Switzerland.

And then, on the other side of the bracket, barring upsets, awaits Federer.

A Federer-Djokovic Monday night final?

A rematch of the Wimbledon final that was a classic?

Looks like we may have more great expectations at the U.S. Open.