INDIANAPOLIS -- By the end of the third quarter, Cardinals receiver J.J. Nelson had caught three passes for 44 yards and was ahead of his average pace heading into the fourth quarter.

Then he turned on the afterburners.

He caught two passes for 76 yards in the fourth quarter, including a 45-yard touchdown that set Arizona’s comeback win into the motion. The Indianapolis Colts were in a four-seam coverage, so the safety was staying low. Nelson knew if he could beat the cornerback that all he’d have to do is get behind the safety. With his speed, he knew he could do it and he did -- even with two defensive backs draped on him.

"He continuously makes big plays but he can make the easy ones, the second ones, too," quarterback Carson Palmer said. "He’s just one of those guys that the lights come on and he’s right where you need him to be, making tough, contested catches."

Brown has emerged as one of Arizona’s best late-game scoring threats. He has six touchdown catches in his last seven games dating back to last season, and four have come in the fourth quarter, according to ESPN Stats & Information. He has also turned in the second- and third-best receiving games of his career within the last four games, dating back to Week 16 of last season in Seattle when he had 132 yards and a touchdown on three catches. He had five catches for 120 yards and a touchdown on Sunday in Indianapolis.

With fellow receiver John Brown out for Sunday’s game with a quad injury, Nelson knew he'd have an expanded role. But coach Bruce Arians said Nelson should be having this type of performance every week, not just when a teammate is down.

"That’s what he is capable of," Arians said. "He is capable of a big play like that every game."

Nelson nearly had another impressive touchdown catch in the second quarter when Palmer found him in the back corner of the end zone. Nelson contorted his body to try to keep his feet in bounds. The play was initially ruled a touchdown but overturned by replay.

Nelson was also the target of a Palmer pass later in the second quarter that was intercepted by Indianapolis’ Malik Hooker on the 3-yard line.

Yet even without making those two catches, Nelson still changed the game with his speed and strengthened his case as one of the Cards' most potent threats.

"He’s got a knack for making plays, especially down in the red zone," wide receiver Larry Fitzgerald said. "For a guy that small he’s able to get some separation and he’s got really strong hands at the point in attack."