Instant observations: James Harden's 45 points carry Sixers to Game 1 win vs. Celtics

The Sixers stole Game 1 in Boston behind James Harden's playoff career high of 45 points, overcoming the absence of Joel Embiid in a 119-115 victory.

Here's what I saw.

The Good

• James Harden told reporters on Sunday afternoon that Joel Embiid's absence would mean an uptick in aggression for him, which sounds like a, "Yeah, duh" statement until you consider how out of his depth Harden looked at times in round one. But he came out of the tunnel with flames shooting out of his eyes, and with the Celtics setting up on defense in a way that tilts in his favor, Harden threw an opening round haymaker that allowed the Sixers to keep pace with Boston.

The Celtics decided their best approach to defend pick-and-rolls was to sit back in drop coverage, with Boston not super comfortable switching either of Robert Williams III or Al Horford on Harden. Philadelphia's veteran guard stared down the deep drop Boston was sitting in and just sort of laughed at it, pulling out every possible trick in the book to ruin that sagging scheme. The biggest equalizer was his pull-up shooting from three — Harden finished the first half 3/5 from deep, with each of those shots lightly contested for a player of his caliber. 

To get rolling as a shooter, though, Harden worked the midrange early in this game, with Horford and Williams falling back toward the rim as Harden poked and prodded from the in-between area of the floor. You don't have to worry about making layups if you just make a boatload of jumpers, and this was a masterclass from Harden in that regard, teardrops and runners and stepbacks and all sorts of tricks on display at TD Garden.

On the mental side of the game, I thought an important early sign was Harden not changing his approach after Marcus Smart undercut him on a pull-up three. There have been many moments throughout Harden's career where he has been lost in the battle to draw fouls, overly concerned with what the refs are and aren't calling. There was little to none of that on Monday night, with Harden in seek-and-destroy mode before and after that dust-up with Smart. And even as he had to play through contact to get his, Harden continued to play strong instead of hoping to sell the contact, trusting that he could outmuscle smaller Celtics players on his way toward the hoop.

But this game was ultimately about Harden eating drop coverage alive at the end of the day. Boston refused to go away from their approach defending him, and Harden kept calling up screens, waiting for his space, and stepping into a fairly good look from deep. He did everything in his power to keep Philadelphia in this game.

With the game on the line, the Celtics finally decided to stop dropping Horford toward the rim against Harden in pick-and-rolls. Horford switched onto Harden in the game's most important possession, and Harden decided to call game.

In this game, Harden's season-long message about giving himself up for the team really started to hit home. Here is a first-ballot Hall of Famer, one of the most decorated scorers in history, taking a backseat to Joel Embiid and (on a lot of nights) the role players surrounding that duo. Being able to summon this type of performance in a huge spot for the team — even if it took a trip to Vegas and a week off to get it — is something the Sixers simply have not had in playoff runs of the past.

All-time Sixers playoff performance.

• De'Anthony Melton is a frustrating player to watch when he's in one of his valleys, all confidence and no touch, but I think it is abundantly clear he is a 16-game player. He was one of Philadelphia's few positives on the defensive end of the floor, throwing some gunk in the gears of Boston's high-flying machine, and his lights-out shooting was one of the only things keeping the Sixers in this one.

The best position Melton can be in is one where his decision-making process is simplified, next to another ballhandler or offensive hub where he can focus on straight-line drives or catch-and-shoot jumpers. Philadelphia's other ballhandlers did a great job of creating separation on the perimeter, causing collapses from the Celtics defense that often led to open threes for Melton. But he did plenty of his own good work — Melton had at least a couple of makes on the move, shooting over outstretched arms, and his work to relocate and maintain excellent spacing helped facilitate great offense for Philly.

And then, right on cue, he had some mind-boggling plays on-ball for the Sixers in the second half. But you have to take the bad with the good. 

• MORE ON THE SIXERS
• Stats that put James Harden's instant-classic Game 1 into context
  
• Vintage James Harden gives Sixers chance to steal series from Boston
  
• Paul Reed is earning trust from Sixers one day, one play at a time
  

• It wasn't a 30-bomb, it wasn't a performance that will set aside all his struggles against them over the years, but Tyrese Maxey continues to show the danger he poses as a shooter in all sorts of situations. Getting a couple of three-point shots to go down is all it took to unleash downhill Maxey, the guy who people were initially excited to have when they drafted him out of Kentucky.

During an early-third barrage from Maxey, he came up with two of his most ridiculous finishes of the year, scoop layups going to his right that were as difficult as layup attempts get. Go to your local gym, ask a buddy to defend you at even 50 percent effort, and see if you can replicate this one.

That's the thing with Maxey's speed — your pace is only valuable if you're able to stay in control as you use it, and there were moments in round one where he couldn't find the balance. There was no such problem in Game 1. 

Unfortunately, Maxey ran cold in the fourth quarter, and worse than that, Maxey had to play with foul trouble for the most pivotal stretch of the game. He was so scared of picking up that sixth foul that he essentially just gave up on pretending to defend Marcus Smart, escorting him to the rim with the worst case of matador defense I've ever seen in a playoff game. 

But Maxey continued to battle late in this game, scoring a difficult layup through contact at the rim to cut the lead to one in the final two minutes. And with Boston completely out of sorts on a critical defensive possession, it was Maxey who was waiting in the passing lane and ready to strike, catching an errant Malcolm Brogdon pass to go to the house for an important two points.

• P.J. Tucker is just an absolute pain in the ass in the best way possible. In a game with few whistles, he took full advantage of the physicality he was able to play with.