A week ago, TJ Jones was jobless, hanging out with his family at home in Atlanta watching the Giants’ season-opening loss to the Cowboys on television.

On Sunday, the 27-year-old receiver was back in the Giants uniform he wore in training camp and preseason before he was cut Labor Day weekend, standing out as one of the bright spots in an otherwise dismal 28-14 home-opener loss to the Bills at MetLife Stadium.

With the Giants’ receiving corps decimated with injuries, Jones was re-signed last week and he caught four passes for 38 yards, including a 4-yard touchdown reception with 11:56 remaining in the game to cut the Bills lead to 21-14.

He also had a 60-yard punt return that gave the Giants the ball deep in Buffalo territory late in the first half that should have led to points, but went for naught when a deflected Eli Manning pass was picked off in the red zone with 47 seconds remaining.

Jones, who was with the Lions from 2014 through last season, catching 64 passes for 814 yards and four touchdowns, called Sunday’s score “probably the prettiest touchdown I ever had.”

He caught the pass in the back of the end zone with Bills cornerback Levi Wallace draped all over him as he kept two feet inbounds.

“On that specific route, I was not the primary read, I was the secondary read,’’ Jones said. “But you’re told, ‘Run it to win,’ because if the first one doesn’t work out … you know if there’s only two options to throw, you’re one of them.’’

Jones said the delayed call by the ref in the end zone left him wondering if he had actually scored his first touchdown as a Giant.

“The ref was kind of slow,’’ Jones said. “I’m like, ‘Did I score?’ He was like, ‘You scored.’ I didn’t know how to celebrate. I kind of blacked out a little bit. I was just excited to get the first touchdown of the year out of the way, so when I did, I was speechless.”

Jones had shown flashes of this form in preseason, when he produced 12 catches for 146 yards and two touchdowns in four games.

“It felt great to come back from being at home the last 10 days,’’ Jones said. “This is the place I wanted to come back to after they let me go — regardless of when it would have happened. I was working out in Atlanta, hanging out with my wife and kids. It’s great to be with my family. The timing of the year just wasn’t the best.

“But I’m a glass half-full guy. I could choose to sit at home and sulk and not work out and be bummed that I’m not with a team. Or I can work out, enjoy the extra hours I get with my family, knowing that eventually the call is going to come, and when it does come, I have to be ready to work.’’

With starting receiver Sterling Shepard out for the game in concussion protocol and Cody Latimer suffering a concussion in Sunday’s game, Jones showed he was more than ready to work.