Until guard Destinee Walker drilled a fast-break three from the right corner more than six minutes into the game Saturday, Radford had been unable to penetrate the suffocating defense of the Maryland women’s basketball team.

The bucket had an instant settling effect. After an ice-cold start, the Highlanders trimmed a 14-point first-quarter deficit to 24-20 by midway through the second, as they appeared to have adjusted to a defense that flummoxed them at the start.

But the early adaptation proved to be little more than a calm before the storm.

The No. 3-seed Terps ended the half on a gritty 9-0 run, blanking Radford for the final five minutes. The visitors’ struggles didn’t dissipate after the halftime buzzer. By the time the No. 14-seed Highlanders made their next shot — four minutes into the third period and nine minutes after their previous make — Maryland had built an insurmountable advantage through varied defensive looks and its size.

One game after their worst defensive outing of the season in the Big Ten tournament championship, the Terps put together one of their best, a 73-51 triumph in the NCAA tournament opener.

“We had the [Big Ten] tournament; that’s over, we can’t get it back,” guard Kaila Charles said. “We weren’t looking behind.”

[Read more: Maryland women’s basketball rolls past Radford, 73-51, in first round of NCAA tournament]

After Maryland’s subpar showing on defense against Iowa the last time it took the floor, the team had no choice but to go back to the drawing board.

The Hawkeyes exploded for 90 points — the most the Terps have given up all year — as forward Megan Gustafson torched the tournament’s top seed for a season-high 45 points.

On Saturday, Maryland didn’t face anyone close to the All-American.

Radford was held to a derisory 29.7 percent from the field, as the Big South champion had no answer for the Terps’ superior athleticism. The home side repeatedly jumped passing lanes, and the Highlanders, frequently misjudging Maryland’s length, obliged with 17 giveaways.

“In the Big South, there’s nobody that long, especially [forward Shakira Austin],” Walker said. “She and the rest of the team is long.”

Austin, an All-Big Ten Defensive team selection, racked up four steals against Radford by encroaching passing lanes with her 6-foot-5 frame.

Meanwhile, coach Brenda Frese intermittently switched to zone to further keep the visitors off balance. As Maryland’s steals rose to 11 — its most since facing Indiana on Jan. 27 — it became increasingly obvious how ill-prepared the Highlanders were for the Terps’ defense.

“We’ve seen zone and press all year. We haven’t seen length like that,” Radford center Sydney Nunley said. “I really do believe it was just the length, not so much about how they were defending us.”

[Read more: Kaila Charles is hitting her stride as Maryland basketball prepares for the NCAA tournament]

Radford’s 51-point total was the fewest Maryland had allowed in more than a month, since a 62-48 win over then-No. 20 Rutgers on Feb. 10, but the Big Ten regular season champions were far from one-dimensional.

After notching a relatively pedestrian 33 points in the first half, the Terps exploded for 25 in the third quarter alone. Guard Taylor Mikesell, a game after being held without a triple for the first time this season against Iowa, scored eight points — including a pair of threes — in the third frame to heighten Maryland’s edge to as high as 25 points.

Both long-range makes came on the fast break.

“It all started on the defensive end, and we started flowing together,” Mikesell said. “My teammates found me in transition and they started going in.”

If you ask Radford coach Mike McGuire, the game was decided by the glacial start that preceded Walker’s sixth-minute three-pointer. The Terps (29-4) were intrusive during the early stages, and despite a brief run by the Highlanders to get within arm’s reach, the higher seed eventually rekindled their success at the onset to pull away.

The win sets up a date with No. 6-seed UCLA (21-12) in a second-round tilt on Monday, and the Bruins won’t be surprised by Maryland’s size.

“Obviously the start to the game was a big factor in how we played,” McGuire said. “Our start set the tone for the game, and it was something we couldn’t recover from.”