Washington: Defending champions Cleveland and powerhouse Golden State enter Sunday’s start of the playoff semi-finals pushing toward an unprecedented third consecutive NBA Finals showdown, adding more sparks to an already historic rivalry.

Golden State entertains San Antonio in Sunday’s best-of-seven Western Conference final opener while the LeBron James-led Cavaliers await Monday’s game-seven winner between Boston and Washington in an Eastern Conference final that begins Wednesday in Cleveland.

No two teams have ever met for the title in three consecutive seasons, as the Cavs and Warriors could, and only a handful of players have made the NBA Finals seven years in a row, as James could do.

The Warriors beat Cleveland for the 2015 crown and were one win shy of capping a repeat title run last year after a record 73-win campaign only to have James spark the Cavaliers from a 3-1 deficit to the greatest comeback in NBA Finals history, taking the trophy in seven games.

So it’s no wonder that Warriors guard Stephen Curry, the two-time reigning NBA Most Valuable Player, can ponder a match-up with the Cavs even as he admits Golden State has plenty of work ahead to oust the Spurs.

“We’ll hammer it out when we get there but we’ve got four more wins to go,” Curry said. “We’ll be keeping an eye on them.”

Both the Warriors and Cavaliers have swept through the first two playoff rounds without dropping a game. Golden State forward Draymond Green said he had hoped to see more from Cleveland’s East rivals.

“I thought teams would compete a little harder,” Green said. “When you watch Cleveland play, you only watching one side of good basketball. That’s kind of weak.”

James does not diminish Cleveland’s strong start in eliminating Indiana and Toronto, saying, “It’s rewarding when you can advance. It’s not just given to you. You have to go out and earn it.”

But even “King James” admits: “We have another level and we believe we can get there.”

In the playoffs, James is averaging 34.4 points, 9.1 rebounds, 7.1 assists and 2.1 steals per game. And last year, he became the first player in NBA history to lead the finals in every major statistical category.

“I’m going to let you guys talk about that as far as if this is the most complete I’ve been in my career,” James told reporters.