4:48 PM ET

The lack of elite competition along the way was one of the doubts hanging over the Celtics as they have completely transformed their season over the past several weeks.

On Sunday afternoon, the Brooklyn Nets traveled to Boston to play the Celtics in a game with Kevin Durant and Kyrie Irving playing together for the fourth time this season.

But while he was great, he wasn't as good as Jayson Tatum.

The Celtics won their 14th game of the season on Sunday, thanks to a 54-point performance by the young star, who tied Larry Bird for the most in Celtics history.

As a competitor night in, night out, but especially games like this, those are the kinds of moments that you remember as a kid, when you were on one of the better teams in the league with two of the best guys.

You try to make the most of those opportunities.

On Sunday, he put together one of the best games of his career to lead Boston past a Nets team that has now lost 17 of its last 20 games.

While Irving had 19 points on 18 shots, and was booed relentlessly whenever he touched the ball, Durant went for 37 points, six rebound, eight assists and two blocks, while he did have seven turnovers.

In the kind of performance that showcased his ability to do everything at the offensive end, Tatum nearly matched their scoring output by himself, and did so by scoring at every level, from the 3-point line, driving to the rim and getting to the foul line.

Jaylen Brown, who scored 21 points in 35 minutes in his first game back from an ankle injury, said that this man to the left was unstoppable.

Boston has seen its level of play rise over the past few weeks, and that is part of the reason why. Marcus Smart applauded his teammate for how his game has grown, and said he has noticed that he has been playing smarter.

Smart said that he stopped trying to force it and made the game easy for himself. He has the legs late in the fourth quarter to take over games.

Having those legs in crunch time is what it is about when you are a great player. Picking your spots wisely is how you get everyone else involved. He and Jaylen are doing a great job. The reason we are doing what we are doing is because they both are. Good players that get us going on the offensive end, making sure we get great shots either for themselves or for their teammates.

The challenge of stopping Brooklyn would be difficult for the Celtics, according to coach Ime Udoka. Boston entered Sunday with the NBA's best defense on a per possession basis, but fell one-tenth of a point behind the Golden State Warriors once Sunday's game was included.

The Celtics knew they had to win this game with offense. Boston was able to do that thanks to the rest of the Celtics shooting a combined 9-for-21 from 3-point range.

It is possible for someone like myself or Jaylen to have nights like this.

It opens everything up for us when we get those open looks. We know how hard we can be on defense. We will be special when we match that energy on offense.

Boston has had a lot of special moments over the past several weeks, as the Celtics have completely flipped the script on their season and are now firmly ensconced in fifth place, and are within one-and-a-half games of the second spot in the Eastern Conference.

Boston has mostly done that on the backs of playing overmatched and injured opponents. The Celtics have defeated the Hawks, Memphis, and the Warriors this week, with Brown not playing after hurting his ankle in the opening minutes.

It is hard to argue that anymore. With the way the Celtics are playing, they can go toe-to-toe with anyone and come out on top.

This is the time to get ready for the playoffs, Brown said. As the days go by, more and more of the focus is important. Our group is just trying to get better each and every game.

Along the course of the season, we have been doing that. It did not start off that way. It was a marathon, not a sprint, and it started off looking bad. I am glad our guys stayed the course because I think we still have a long way to go.