When the back of Reggie Jackson’s head hit the hardwood late in the second quarter Tuesday, the thud following a hard fall could be heard throughout Moda Center.

Jackson lay prone on the ground for several second as five Clippers teammates rushed to check on their starting point guard.

It was an ominous sign for a Clippers team already missing four of its most dangerous players. One quarter later, even after Jackson returned, it was the Clippers who appeared lifeless as their deficit grew to 18 with only 15 minutes remaining.

No one is yet sure what this version of the Clippers will become, whether a title pursuit is truly within the realm of possibility, or whether they can remain healthy enough to turn potential into reality. But on a late November evening in a game missing its marquee stars, the Clippers transformed into a madcap group that suddenly overwhelmed Portland in a hellacious fourth quarter, a comeback that left Norman Powell, the former Trail Blazer, yelling into the crowd and pumping his fist in the final seconds.

Powell repeatedly punished the Blazers with drives to the rim, scoring five layups in the final quarter. After Jackson, who finished with 24 points, played the entire second half. He walked to the locker room yelling to no one in particular about his fall, “Boy, am I going to feel that one on the plane.”

It will be a happy ride to Salt Lake City for Wednesday’s game after pulling off the unexpected and improving to 13-9 by featuring a closing lineup that included rookie Moussa Diabate, who had awoken in Ontario with the team’s G League franchise with all of six NBA minutes under his belt. The 6-foot-9 forward from Michigan played every second of the fourth quarter.

The comeback also featured an unlikely contributor in Jason Preston, the backup point guard who sat out last season with a foot injury and scored his first NBA basket on a three-pointer in the first quarter. Preston was needed because John Wall, who typically handles the bench offense, did not play because of left knee injury management, continuing the team’s practice of not playing Wall on consecutive nights.

The Clippers gave up 37 points to Anfernee Simons and 32 to Jerami Grant, but focused the full intensity of their defensive efforts on that duo late in the game, forcing players such as Justise Winslow and Josh Hart to blunt their rally. It never happened, as the Clippers made 12 of their 21 shots in the fourth quarter, plus nine of their 12 free throws.

Trailing 110-108 with 2:35 remaining, Jackson’s drive into the key set up a goahead three-pointer by Nicolas Batum, the former Trail Blazer who spent his first seven seasons in Portland.

After a Powell layup pushed the Clippers lead to 115-112 with 1:35 remaining, Diabate blocked a Simons shot and began a procession of fans toward the exits. Portland never scored again. The Trail Blazers played without star guard Damian Lillard.