Veteran forward Marshall (right) made it a birthday to remember

Marshall's 18 points from beyond the arc helped the Cavaliers secure a 4-2 series win and they now face Detroit.

San Antonio sealed their place in the Western finals with a 114-106 victory over Phoenix, also winning 4-2 overall.

Manu Ginobili had 33 points and 11 rebounds to help set up a best-of-seven showdown with the Utah Jazz.

Cleveland coach Mike Brown was delighted with Marshall's haul as the Cavs reached the Eastern finals for the first time in 15 years.

"Donyell Marshall, I can't say enough about the man," Brown said. "He stepped up and hit big shot after big shot after big shot for us."

Marshall averaged seven points a game for Cleveland during the season.

"To actually go out there and help close this series out, never having been this far (in the play-offs), it's great, it's awesome," he said.

In San Antonio, Ginobili was supported by Tony Parker's 30 points for the Spurs, who led by 20 early in the fourth quarter but had to weather a late Phoenix comeback.

Tim Duncan had also 24 points and 13 rebounds for the hosts, while a game-high 38 points and 12 rebounds for the Suns offered little consolation for Amare Stoudemire.