Ben Simmons, Philadelphia 76ers chasing NBA history

Ben Simmons, with a smile on his face and a diamond-studded boxing kangaroo chain hanging around his neck, declared the Philadelphia 76ers were ready to make NBA playoffs history.

The 21-year-old Australian rookie made the bold proclamation minutes after his Sixers staved off elimination in their series against the Boston Celtics with a 103-92 victory in Philadelphia on Monday.

"I'm not ready to go home and start my vacation," Simmons, who had a double-double of 19 points, 13 rebounds and five assists, told reporters in the post-game press conference.

"Definitely not."

It was the 76ers' first win in the series and they still trail 3-1, with Boston needing just one victory to move on to the eastern conference finals.

Simmons and the 76ers are aiming to win four-straight games to become the first team in NBA history to come back from a 0-3 series deficit in the best-of-seven series.

There have been 129 teams attempt a comeback from three losses in a two to start a series.

All failed.

Simmons and his 76ers now head to Boston for Wednesday's game five knowing a loss will end their season.

"We believe our time is now," he said.

"It is going to take a lot, but it is just the way our mindset is."

The 76ers were so confident of winning game four they arrived at the Wells Fargo Center arena with their luggage and a plane on the tarmac ready to fly them to Boston.

Celtics coach Brad Stevens has been the master strategist in the series but Brown countered with the game-winning move by shaking up his starting line-up.

He replaced forward Robert Covington, who missed all eight field goal attempts in game three, with the energetic but unheralded TJ McConnell.

The back-up point guard took some of the ball-handling pressure off Simmons and made inspirational plays with a career high 19 points.

"There's an injection of energy you immediately know you are going to get with him," Brown said.

Simmons had error-filled games in the game two and three losses but was determined to play more aggressively and take open shots in the game four victory.

His aggression backfired early, missing five of his first six field goals, but midway through the second quarter he found his range.

Simmons frustrated Brown with reckless passes leading to turnovers in the final quarter but he was more relaxed in the press conference when asked about his boxing kangaroo chain.

"The bling?" Simmons replied.

"That's just something to represent home."

The Celtics' Australian centre Aron Baynes had another strong game battling with 76ers' All-Star Joel Embiid with nine points and six rebounds.

Baynes hit two three-pointers, although he missed four others including an air ball, while Embiid had 15 points and 13 rebounds.