George Washington’s 17-point lead had dwindled to nothing in the second half against esteemed Temple on Sunday, a major test of the Colonials’ mettle during an ambitious opening stretch to the men’s basketball season.

“It’s easy for a young team to just fold,” Coach Maurice Joseph said afterward. “You know what? They erased a [big] lead; let’s warm the buses up.”

Instead, the Colonials regathered themselves and survived two potential game-tying shots to secure an impressive 71-67 victory in what was their last appearance in the BB&T Classic for the time being.

As the game before a sparse crowd at Capital One Arena tightened, Joseph thought, “Now let’s test our character. Let’s see where we are in our progression as a team. Let’s see where our grit and toughness is.”

He saw it in the last six minutes. The Colonials went ahead for good on an inbounds lob from Jair Bolden to Patrick Steeves with about five minutes left. Bolden made a three-pointer with the shot clock about to expire. Yuta Watanabe blocked a layup attempt in the final minute.

With a rotation of two freshmen, three sophomores and a graduate student in his first season in Foggy Bottom, GW (4-4) had taken its lumps against Florida State, Xavier and Kansas State. Penn State and No. 10 Miami await the next two weekends.

But the Colonials showed some blossoming maturity against Temple (4-2), which had beaten South Carolina, a 2017 Final Four team, on Thursday.

Bolden and Watanabe scored 17 points apiece and freshman Justin Mazzulla contributed a career-high nine by making all four shot attempts in a reserve role. The Colonials led for more than 36 minutes and shot 68 percent in the first half and 60 percent overall, including 9 of 16 three-pointers.

“We were up 15 in the first half, and they were coming back, but we stick together and always talk to each other,” said Yatanabe, the lone four-year player. “We learned a lot today. It’s a huge win for us.”

Averaging six three-pointers per game, the Colonials made six in the first nine minutes. They were comfortable running their offense, finding good shots and making smart passes for easy baskets.

While limiting Temple to two field goals in the last six minutes of the half, the Colonials continued to hum in possession. Steeves supplied Arnaldo Toro for a layup and 13-point lead and later banked in a leaner at the buzzer to give GW a 40-25 advantage.

“GW in the first half obviously made just about every shot they took,” Owls Coach Fran Dunphy said of the Colonials’ 17-for-25 accuracy. “Some of that is them. Some of that is us.”

After the lead swelled to 17 on Steeves’s basket to start the second half, the Colonials began to crack. Quality shot opportunities disappeared, and turnovers mounted.

Quinton Rose and Shizz Alston Jr. accounted for 14 consecutive points as the Owls pulled within six with 12:55 left. The lead was 11 when Temple scored 10 straight. Moments later, Alston’s three-pointer with 6:25 left evened the game.

The momentum was flowing Temple’s way, but GW showed its poise.

“Our core is young, and the majority of our team is young, but we lean on guys who have been there and played a lot more college basketball games than a lot of us,” Bolden said. “We have great leaders who never get down whether we’re turning the ball over or not scoring or they are scoring at the other end.”

After Temple closed to 69-67, Bolden made 1 of 2 free throws with 20 seconds left. Obi Enechionyia missed a three-pointer. Bolden had the rebound stripped from him. Rose’s three-pointer was off the mark.

GW’s Terry Nolan Jr. was fouled on the rebound and made a free throw with a half-second left to clinch victory. And with it, the Colonials relished an indelible memory from a tournament they have participated in 22 times.

“Guys have enjoyed playing in this arena — it’s been tremendous,” Joseph said. “But I’m looking forward to our future and being able to be a little more creative with our schedule and getting an opportunity to play some different teams in some different venues.”