By Jace Frederick

St. Paul Pioneer Press

MINNEAPOLIS — The Timberwolves opened the second half comfortably in front — a spot they’ve been in countless times before.

They led Boston 52-42.

Previously, the Timberwolves had difficulty holding leads in the third quarter, as collapses cost Minnesota games it should have won. That trend defined the first 10 games of the season.

That didn’t happen Monday night, as Minnesota outscored its opponent in the third quarter for just the second time all season. The Timberwolves expanded their lead to 81-68 going to the fourth.

But the problem wasn’t fixed, rather delayed. The fourth quarter provided the horrors Minnesota normally reserves for the third. Boston scored the first 17 points of the final frame on its way to a 99-93 victory at Target Center.

Minnesota was outscored 31-12 in the final period.

“Well, the fourth quarter is different,” a subdued Tom Thibodeau said after the game. “It just shows, you never let your guard down and you have to strive to be a 48-minute team and we’re not doing that right now.”

The Wolves coach said Minnesota needs to be tougher with the lead, a statement verified by the five halftime leads Thibodeau’s squad has squandered this season.

“We put a lot of time and effort into it, and we just (let it) slip away all the time,” Wolves center Gorgui Dieng said. “We need to find a way to keep that lead. It’s frustrating, seriously.”

The Timberwolves (4-9) were so strong defensively through three quarters, holding Boston to 42 percent shooting, while outrebounding the Celtics 41-28.