The NBA’s defending champions are just one game away from crashing out of the playoffs while the Los Angeles Lakers are on the verge of continuing their post-season charge.

Lonnie Walker IV was the unlikely hero for the Lakers, scoring 15 points in the fourth quarter as L.A. took a 3-1 series lead with a 104-101 win over the Golden State Warriors in Game 4.

The 15 points in the final quarter were the only ones Walker managed all game but none of that mattered because the 24-year-old stood up when the Lakers needed him most.

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LeBron James certainly noticed, declaring post-game that the Lakers would not have won if it wasn’t for Walker.

“I’ve been telling him, ‘Lonnie stay ready, we’re going to need you at some point’… for him to be as young as he is and for him to have that professionalism, come out and stay ready for when his number was called, we don’t win this game without Lonnie Walker without him,” James said.

Steph Curry was at his playmaking best in defeat, dishing out 14 assists along with 31 points and 10 rebounds for his third career-triple double in the playoffs.

Klay Thompson though struggled to get into his usual shooting rhythm, going 3-for-9 from deep as the Warriors shot just 29.3 per cent of 3-pointers as a team.

The series between the Lakers and Warriors has quickly proven an ongoing — and fast-changing — chess match, with Steve Kerr the first coach to make necessary adjustments before Darvin Ham did the same in Game 3.

Most notable was the decision to change defensive assignments, with Jared Vanerbilt shifting off Steph Curry to guard Draymond Green while Austin Reaves matched up against the Golden State sharpshooter.

It paid off in a big 127-97 win and put the pressure immediately back on Kerr and the Warriors to respond.

Earlier in the series in Game 2, Kerr went small and replaced Kevon Looney with JaMychal Green in the starting lineup to spread out the court.

On Tuesday in Game 4, Kerr started small again but this time had Gary Payton II come into the starting team for the first time since Game 2 in the second-round series against Memphis last year.

“What he wants also is to be able to have guys who can make plays behind the defence when the Lakers blitz those pick-and-rolls on those shooters,” Stan van Gundy said in commentary.

“We know Draymond Green can make those plays, so can Gary Payton.”

That wasn’t the only change the Warriors made though. They also made a concerted effort to put Davis in every pick-and-roll action, hence dragging him out of the paint.

It opened up driving lines for Golden State, adding more variety to its offence and resulting in the Warriors outscoring the Lakers 32-22 in the paint on the way to a 52-49 halftime lead.

“Every time I’m in the Warriors huddle, every time they’re talking about Anthony Davis they’re trying to get him defensive to move out on the perimeter,” sideline reporter Chris Haynes said on TNT’s coverage of Tuesday’s game.

“They’re talking about whoever AD is guarding they want to involve him in dribble hand-offs or pick-and-roll action. They want AD away from the basket and not to be a shot-blocking threat.”

Coincidentally, just as Haynes was speaking Davis was dragged up to the perimeter as Curry found an open Draymond Green for the finish.

Curry found plenty of success in the first half while operating out of the high pick-and-roll, finishing with 17 points, seven assists and just as many boards.

According to ESPN Stats & Info, Curry scored or assisted on 32 of the Warriors’ 49 points in the first half and shot 7-for-10 off his passes.

Davis led the Lakers with 19 points, six rebounds and two assists while James had 11 points, five rebounds and two assists.

Both teams were having all kinds of problems from deep, combining to shoot 7-for-30 as Jordan Poole (zero points) and Thompson (three points) struggled as a result.

Fortunately for the Warriors Curry was in the zone and stepped up to lead Golden State on a 14-8 run to end the second quarter and take a 52-49 lead into halftime.

The Warriors extended that lead to 57-49 with the first five points of the third quarter before Austin Reaves and James combined to score 10-straight points as the Lakers regained the lead.

It prompted Golden State into a timeout and the lead was short-lived for L.A. as Golden State went on a 11-0 run of its own, with Payton II scoring seven of those points.

The Lakers were struggling to keep up the Warriors, particularly in transition defence as Golden State pushed the pace.

But a few turnovers from the Warriors and more buckets for James and Reaves brought the Lakers to 77-70.

A disruptive Dennis Schroder then stole the ball off Donte DiVincenzo and made a tough driving layup to cap off a 7-0 run for the Lakers in the space of 90 seconds.

The remainder of the third quarter though was yet another reminder to live in the moment and appreciate Curry and James for what they are — two all-time greats who could be going at it for one final time in the post-season.

Curry continued to put on a playmaking masterclass, going behind the back at one point for DiVincenzo as James willed the Lakers back into the game.

Still, the Lakers would need just a little bit more LeBron magic heading into the final quarter trailing 84-77.

The Lakers superstar did just that, inspiring the Lakers to a 9-0 run to open the quarter and take a 86-84 lead.

First, James found Walker for a 3-pointer before scoring himself and then dishing it out to Davis in the paint.

The Warriors needed something to stop the Lakers’ charge and predictably it was Curry who stood tall, pulling up over Davis in transition before making a four-point play moments later.

But with Reaves and Walker also continuing to come up with big plays for the Lakers, the result was from far settled as the Warriors took a 96-94 lead into the last four minutes.

Speaking of which, Walker again came up clutch late in the quarter to give the Lakers a 100-99 lead before James drained two free throws to extend the buffer to three points.

“Anthony who? LeBron who? The go-to guy for the Lakers in the fourth is Lonnie Walker,” van Gundy said.

Of course, Curry then answered back with a driving layup to make it a one-point game again but then missed a long 3-point shot for the leader as Walker hustled for the rebound and was fouled.

Walker went on to make both free throws, giving the Lakers a 104-101 lead with 15 seconds on the clock and the Warriors one final chance to send the game to overtime.

But in a calamitous ending to the game Green turned the ball over cheaply before Curry came down with the jump ball only to throw it away as he fell to the ground.

The Warriors and Lakers then used their last timeouts but with 1.7 seconds on the clock it was a mere formality for L.A., who took Game 4 and a 3-1 series lead.

HEAT JUST ONE WIN AWAY FROM CONTINUING FAIRYTALE RUN (via AFP)

Earlier, Jimmy Butler scored 27 points as the Miami Heat outmuscled the New York Knicks to take a commanding 3-1 lead in their best-of-seven NBA Eastern Conference playoff series.

Butler was one of five Miami players to finish in double digits as the Heat edged to a 109-101 victory that leaves the eighth seeds just one win away from a place in the Eastern Conference finals.

It was another ruthlessly clinical performance from Miami, who looked hungrier and sharper throughout at both ends of the court.

Miami hauled down 13 offensive rebounds to New York’s eight and out-hustled New York defensively with 31 defensive rebounds to the Knicks’ 27.

Miami coach Erik Spoelstra said his team was now reaping dividends from their resilience forged in the regular season, when they were forced to battle through the play-in tournament to reach the playoffs.

“We found the value in the grind of the regular season, the grind and the struggle,” Spoelstra said.

“Without that struggle — where we had to find different solutions to win, with different guys stepping up for these kind of moments — if we didn’t do that in the regular season you have zero chance to be able to do that in the playoffs.

“There’s nothing easy about the regular season, and nothing easy about the postseason. But if you can come to grips with that it can make you collectively stronger.”

The Knicks’ shooting from three-point range was also found lacking, with New York making just 9-of-28 from beyond the arc in contrast to Miami’s 13-of-39.

Butler finished with 27 points, 10 assists and six rebounds while Bam Adebayo produced another towering defensive display with 23 points and 13 rebounds.

Jalen Brunson led New York’s scorers with 32 points, while RJ Barrett added 24 and Julius Randle 20.

The Knicks now must win all three of their remaining games to stay alive in the playoffs, while Miami can book their place in the conference finals with a win in game five in New York on Thursday [AEST].