Play-off debutant Devin Booker starred for Phoenix Suns in a 99-90 victory over Los Angeles Lakers.
Booker had 34 points, while fellow play-off first-timer Deandre Ayton contributed 21 points. The only negative for the Suns was a shoulder injury suffered by Chris Paul.
There was late drama at Madison Square Garden as Trae Young grabbed the winning score in the last second to earn Atlanta Hawks a 107-105 victory over the New York Knicks.
Young, who finished with 32 points, was the target of the home fans throughout but had the last laugh, putting his finger to his lips after a solo effort.
Top seeds the Philadelphia 76ers held off the Washington Wizards 125-118, with Tobias Harris setting a play-off career high with 37 points.
Philadelphia made their move in the third quarter, outscoring their opponents 38-31. Joel Embiid also made a big contribution with 30 points.
There was an upset as the Memphis Grizzlies scored a 112-109 victory over the Utah Jazz.
Dillon Brooks set a new scoring record for a Grizzlies player making his play-off debut with 31 points, while Ja Morant chipped in with 26 points.
The Jazz were without star scorer Donovan Mitchell, who was again absent with an ankle injury, and Bojan Bogdanovic's 29 points did not prove enough.