The Union rolled into the semifinals of Major League Soccer’s tournament at Disney World on Thursday night with a 3-1 win over Sporting Kansas City that featured some terrific goals.

All of the scoring came in the first half, and the Union were lively from the start. Brenden Aaronson was at the center of the fray, starring on a night when scouts from at least a half-dozen European clubs watched him closely.

Jamiro Monteiro opened the scoring in the 24th minute, after a 15-pass buildup. Alejandro Bedoya was key to it, with a feed from midfield to Aaronson that unlocked Kansas City’s midfield. Bedoya kept running as Aaronson played wide to Gaddis, who cut in to Santos, who fed Bedoya with a one-touch pass. Bedoya burst through the back line and beat goalkeeper Tim Melia with a square pass to Monteiro, who had an open net from 6 yards out.

Sergio Santos got the second goal just two minutes later, after the Union cleared a Kansas City free kick. Sporting’s defense was out of sorts, and when Luis Martins misplayed a back pass, Santos was off to the races. He trapped the ball just inside the midfield line, sprinted past Graham Zusi, and chipped Melia after entering the 18-yard box.

“When I saw the opportunity, I took it as best I could,” Santos said, and he sure did.

“You saw tonight just how much he can change the game,” Union manager Jim Curtin said. “You can’t teach speed, you can’t teach decision-making on breakaways, and his ability to stretch the defense’s is really good.”

In the 39th minute, Santos and Aaronson produced the best goal of the bunch. After the Union cleared a Kansas City corner, José Andrés Martínez sprung Bedoya, who fed Aaronson in the middle. The Medford native spun through Zusi and Dániel Sallói, settled the ball with one touch, then played a pass for Santos that split three Kansas City defenders. Santos was wide open 12 yards out and fired in a first-time shot.

“When you get a pass like that, it’s easy,” Santos said.

That play was one of many reasons why Aaronson is drawing European teams’ attention. He completed 10 of 14 passes and had two good shots, both early in the first half.

“The ball he plays on the third goal, that’s a top ball in any league,” Curtin said. “Some players tend to shrink from the occasion. He tends to raise his level and raise his game. I don’t know how much longer I’ll get to coach him for, but I’m going to enjoy every day.”

Alan Pulido scored Sporting’s goal in first-half stoppage time. He came inches from a second in the 49th minute, when he swerved a free kick off Andre Blake’s far post, and Martínez added to the drama with a bicycle-kick clearance.

Santos’ night ended in the 53rd when Ilsinho replaced him. (Martins was yanked at halftime by Sporting’s Delran-born manager Peter Vermes.)

In the 57th, the Union got lucky again. Kansas City’s Johnny Russell put the ball in the net, but did so after coming back from over the end line. That disqualified him from touching the ball, and the referees waved it off.

Przybylko was withdrawn in the 71st for Andrew Wooten, and Martínez nearly forced Curtin to use his final substitution four minutes later. The Venezuelan midfielder collided head-to-head with Sporting’s Roger Espinoza contesting a ball in the air, but continued playing.

That allowed Curtin to save his cards for the 86th minute. Aaronson and Monteiro left for Matt Real and Anthony Fontana. Real went up to the left wing to boost the defense on that side of the field and close the game out.

The Union’s semifinal game will be Wednesday against New York City FC or the Portland Timbers. That quarterfinal is Saturday (10:30 p.m., FS1, UniMás, TUDN), meaning the Union will have two more days’ rest than their next opponent.

Curtin jokingly apologized to his players’ spouses and children back home for “your husbands and your dads being good at soccer, and prolonging this thing another six days.”

He might not be a great comedian, but he will indeed be here all week.