Through an unbeaten run this season, the Oakton boys’ soccer team has been at its best after halftime, always finding a way to preserve the streak in its toughest moments with a strong closing kick.

The top-ranked Cougars were following a familiar script in Tuesday’s Virginia AAA state quarterfinal against Broad Run when sophomore Armand Jeffris ran on to a pass from junior Brian McDaid with only the goalkeeper to beat. After a series of close calls, the sturdy forward finally found the net in the 28th minute and started a run of three goals in nine minutes that powered Oakton to a 4-1 victory over the Spartans in Vienna.

The Cougars advance to the state semifinals for the first time since 2001, meeting Cosby Friday night at Westfield. The Titans stayed alive with a 1-0 four-overtime victory over Landstown.

“We’re more of a second-half team,” said Jeffris, who also added an assist. “When it matters, we get it done. Today, we found a little bit of a different way.”

Oakton (18-0-2) pressured the Broad Run net from the opening whistle, but to the midpoint of the opening half, the Cougars had put just one shot on goal, more often spraying their attempts wildly.

Jeffris leads the team in scoring, but he said he’s also had trouble finishing at times, overthinking chances that he knows should end up in the net. McDaid’s pass in the 28th minute provided such a look, and this time, Jeffris delivered, deftly chipping the sliding keeper for his 15th goal of the season.

“We’ve been there before,” Coach Todd Spitalny said. “We know that we’re going to get chances no matter who we’re playing. We’ve just got to bide our time and we’ll get it.”

Northwest Region runner-up Broad Run (14-5-3) missed a close-range chance to tie seconds after the restart, and the Cougars soon made them pay on the other end.

Four minutes later, junior goalie Patrick Hardtke’s booming goal kick found Jeffris’s head. Junior Cameron Santoro tracked down the flick to convert a breakaway opportunity, sliding a low shot under the lunging Broad Run goalie.

Junior Ben Cisse (two goals) finished the decisive run when he converted a cross from Santoro for the team’s third score in the 37th minute. Staked to a rare comfortable lead in the first half, Oakton cruised from there, moving within two victories of its first state title.

“Ever since our freshman year, Todd has been saying, ‘This is the year, we’re going to win states,’ ” Army-bound senior Christian Ollen said. “That’s been the goal, and I don’t think any of the seniors are going to let anybody slack off. We’ve got two more now.”

Senior Mike Margulis scored Broad Run’s lone goal with a strike from the top of the 18-yard box in the 61st minute.

George Mason heads to state semifinal

Senior Kurt Ellis scored twice as the Mustangs (19-4-1) beat host West Point, 4-0, in a Virginia A state quarterfinal. Seeking its third state title in five years, George Mason will meet Galax in a semifinal Friday morning at Radford.

Ellis got the scoring started in the 16th minute, converting off a pass from junior Cole Hinson. Hinson also assisted Henry Darmstadter’s goal 12 minutes later, and George Mason added two more in the second half, earning a trip back to Radford following an early playoff exit in 2012.

“We had a one-year break,” Coach Frank Spinello said. “That was long enough.”