Portsmouth's Isaac Reiss tries to get two of his game-high 34 points against Bishop Guertin's Eli Youssef during Tuesday night's Division I clash at the Colligadome. (Telegraph photo by TOM KING)

NASHUA – It was a tale of two halves, and of one pretty darn good basketball player outdueling another.

Yes, the Bishop Guertin High School boys team probably expected better things Tuesday night when it headed to the locker room up 43-40 at halftime at the Colligadome against the visiting Portsmouth Clippers.

But thanks to cold shooting and 34 points from Clipper junior Isaac Reiss, the Cards suffered their first loss of the young season, 79-66.

“Tale of two halves, have got to make shots,” Guertin coach Will Horne said after his team fell to 1-1 despite 31 points from Connor McGowan. “We had a lot of opportunities, just didn’t fall. We had 40 in the first half, got to keep pace. … We had a lot of wide open 3’s in the first half, but we had a lot in the second half, too. Just got to bury ’em, got to make some plays.”

It wasn’t complicated. The Clippers stepped up their defensive effort after the Cards had seven open 3’s in the first half but zero in the final 16 minutes. No did they get the dribble penetration they enjoyed in the first two quarters, either.

“The first half made me feel sick, honestly, giving up 43 points in a half,” said Portsmouth coach John Mulvey, back at the helm after a year off. “That was all we talked about at halftime, was defense. Pressure the ball a little bit more and close in on their 3-point shooters because they shot the ball well in the first half.”

Of course, the other factor: Portsmouth junior guard Isaac Reiss, who pumped in a game high 34 points with his smart play and ability to drive to the hoop. When Portsmouth needed a play, Reiss was thee to make it.

“He controlled the tempo for us, controlled the game, second half especially,” Mulvey said. “He’s a very gifted scorer, obviously, he can score from all three levels.”

Guertin had a 41-32 lead with 2:30 left in the first half, but the Clippers showed a preview of what was to come with an 8-2 run to close out the half. They then held the Cards to 11 points in the third quarter to grab a 59-54 lead heading into the final eight minutes.

BG’s Sam Woodward got a putback to cut things to 62-60 a couple of minutes into the Clippers cashed in on the fourth second chance attempt to go up 64-60, and Reiss got a putback to make it 68-60 with 3:39 to go. The Cards got to within six on a McGowan layup with 1:41 left but that’s as close as they’d get. Besides McGowan’s points, BG got 10 from Eli Youssef and nine by Matt Chau. Portsmouth’s Derek Swartz came through with 24 and Ryan Swartz had 10.

The final factor down the stretch when the game was still within reach was the Clippers’ numerous second chance opportunities in the second half after Guertin got their share in the first. The Clippers owned the glass at both ends of the floor in the final 16 minutes.

“They’re a big team size wise,” Horne said. “We knew it was a strength of theirs. … We had to rely on the strength of our guards and their shooting. I guarantee if you look at the numbers we were under 22 percent from 3, and you’re not going to win a lot of games that way.”

Letting leads slip away was a problem for BG a year ago in a non-tourney season. The Cards seemed to see their first half energy zapped in the second half, and it hurt them on the defensive end. Horne would’ve loved to have had more preseason, as teams had less than two weeks.

“We could’ve used one more week of practice,” he said. “A week-and-a-half to start the year, this is not going to be the team people see in February and March.”