SAN ANTONIO — Dig a deep hole. Fight back in the fourth quarter. Suffer heartbreaker against a team with a legitimate star.

Wash. Rinse. Repeat.

The Nets watched another rally fall short, storming to a late lead they couldn’t hold and falling 118-107 to the Spurs before a sellout crowd of 19,016 at Frost Bank Center.

Or more accurately, falling to Victor Wembanyama and Dylan Harper.

The Nets (0-3) are tanking this season in hopes of landing a transformational talent in next year’s draft. They didn’t have far to look to see just what that can do for a franchise, all their great work undone by Wembanyama and Harper.

After erasing a 25-point hole in Friday’s home opener, only to lose to Donovan Mitchell and the Cavaliers, on Sunday, they overturned a 26-point deficit in the third to take a five-point lead in the fourth. But they couldn’t hold it.

Cam Thomas — already playing with a broken nose — needed stitches over his left eye and ice on his right hand. He still poured in a game-high 40 points, albeit with no assists — and no help.

The Nets shot just 39.1 percent against a Wembanyama-led defense.

“I’m all right. Just part of the game, Thomas said. “I’m getting my ass beat out there, but it’s all good. Just got to keep playing, keep pushing.”

Coach Jordi Fernández added: “That’s the CT we need, when he’s engaged and he’s asking his teammates to be in the right spot if he’s asking to run A, B and C. That’s what we need. If we keep adjusting and keep playing hard, we’re going to be in a good place.

“So, proud of the effort. … Now it is: Can we do it before their lead gets too big and play with that urgency that we need?”

Michael Porter Jr. (16 points) and Nic Claxton (10) were the only other Nets in double figures.

“He’s a warrior, man. He still went out there and had 40. You couldn’t stop him,” Claxton said of Thomas. “He was scoring at a really high level. And we need that. That’s his superpower, is scoring. So he’s a warrior for sure.”

It marked Thomas’ 10th 40-point effort, tying him with Kevin Durant for the third most in the Nets’ NBA history, behind only Vince Carter (17) and Kyrie Irving (14). But this team lacks a third option, especially with Ziaire Williams (back) forced out of the game and Egor Dëmin being dominated by Harper.

Meanwhile, Wembanyama had 31 points, 14 rebounds and six blocks in wrecking the Nets offense, while Harper — the second pick in this year’s draft — added 20 points, eight assists and six boards, finishing plus-33.

“He’s really something we’ve never seen before,” Claxton said of Wembanyama.

The Nets trailed 81-55 with 8:47 left in the third after a Stephon Castle 3.

That’s when the Nets defense fueled a 35-7 go-ahead blitz, an extended run that started with Thomas bloodied and getting medical treatment.

“I was still getting stitched up, but I don’t really see what happened. But when I got back, it was just everybody said stay with it. The energy was there,” said Thomas. “[But] we can’t keep starting the third quarters letting them jump on us, and don’t have the other team throw the first punch, and we’re scrambling trying to get back in the game.”

The Nets forced the Spurs to miss 10 of their next 12 shots and got into transition. But instead of challenging Wembanyama, they hit 7-of-11 from deep in that run, with Jalen Wilson’s 3 putting them ahead 90-88 with 10:08 to play.

Tyrese Martin’s free throws with 8:40 left pushed the lead to 97-92, but they couldn’t hold it, allowing 11 unanswered points. They watched as Harper and Wembanyama made huge plays to flip the momentum again.

The duo ran a two-man game, with Harper finding Wembanyama for a 3-pointer that made it 103-97 and essentially ended Brooklyn’s hopes.

The Nets are on to Houston for the tail end of a back-to-back Monday.