Jayson Tatum scored 22 points as the Boston Celtics laid down a postseason marker against the high-flying Cleveland Cavaliers with a 112-105 victory on the road on Tuesday.

In a heavyweight showdown between the Eastern Conference-leading Cavaliers and the second-ranked Celtics, Boston produced a clinical display to seal a deserved win.

Tatum led the Boston scoring but it was the Celtics' balanced offense that proved too much for the Cavaliers.

Tatum was one of five Celtics players to finish in double figures, while Derrick White's 20-point contribution — which included six three-pointers — played a key role in securing a Boston victory.

Kristaps Porzingis finished with 19 points and Jaylen Brown 16 while Donovan Mitchell led the Cleveland scoring with 31 points.

Boston had looked poised to inflict a crushing defeat after outscoring Cleveland 28-15 in the first quarter before opening up a mammoth 20-point lead in the second.

But after trailing 43-23 midway through the second quarter, Cleveland came roaring back to cut the deficit to 10 points at half-time.

The Cavs kept chipping away at the Boston advantage in the second half but some superb shooting by the Celtics ensured the visitors always kept the hosts at arm's length.

Elsewhere, Kyrie Irving scored 34 points but it was not enough to stop the Dallas Mavericks from slipping to a 118-116 defeat against a Philadelphia 76ers line-up buoyed by the return of Joel Embiid.

Embiid, who has missed the past month with a knee and foot injury, produced a superb triple-double comprised of 29 points, 11 rebounds and 10 assists, and scored the go-ahead basket with 22 seconds remaining to help the Sixers claim a precious win.

Tyrese Maxey led the Sixers scoring with 33 points, with 13 assists and four rebounds.

The Mavericks meanwhile were without new recruit Anthony Davis, who was part of the blockbuster trade that sent Luka Doncic to the Los Angeles Lakers. 

Davis is still nursing an abdominal strain but is expected to be ready to make his debut later this week, either against Boston on Thursday or against Houston on Saturday.

In Toronto, Karl-Anthony Towns scored 27 points and hauled down 20 rebounds to help the New York Knicks to a 121-115 win over the Raptors. 

The pre-game ceremony once again saw Canadian fans boo the US national anthem in protest at US President Donald Trump's tariff threats.

In New York, the struggling Brooklyn Nets (17-33) upset the Houston Rockets 99-97 thanks to a D'Angelo Russell three-pointer with three seconds remaining.