Kyrome Lumsden put an immediate mark on the tournament 15 minutes in. Receiving a cross-field ball from Matias Wanchope, Lumsden easily brushed off a challenge, making his way to the end line, before cutting back for James Arteaga to finish from close range.
Three minutes later Dempsey Resich doubled the lead, receiving the ball with his back to goal before turning and curling it neatly to the far post. Resich continued his strong run of form, netting his second moments later to earn a first-half brace. After dropping back to midfield to pick up the ball, Resich played a give-and-go with Charlie Rosenthal to get in the Portland area before calmly finishing.
James Arteaga added a fourth in the 57th minute after being sent through one-on-one by a sublime pass from Rosenthal.
The Timbers arguably looked the better team in possession but the key for LAFC was their ability to break out of the midfield.
Portland's possession did finally start to convert into chances late in the second half, but for a series of wasteful attempts. Generation adidas Cup MVP Noah Santos finally gave the Timbers a late goal, but it was too little, too late as LAFC were already setting up for their second-round meeting with Austin FC.
New York Red Bulls 2 (4), Orlando City SC 2 (3)
RBNY's Jeremiah White pulled a goal back shortly after the hour mark. Just 13 minutes later, Davi Alexandre pulled the score level from the penalty spot.
Sacramento Republic 1 (3), Toronto FC 1 (2)
Omar Marquez and Joshua Nugent traded goals two minutes apart in the first half, as Sacramento would go on to advance in a shootout to set up a rematch for the team's only loss in 2022 against FC United Soccer Club at the MLS NEXT Flex tournament.
Sockers FC 4, FC Dallas 2
The host club crashed out after a strong comeback by Sockers FC. Tadesse Hart gave FC Dallas the lead just before halftime only to see the Illinois club respond immediately through Aaron O'Reilly. O'Reilly added a second before Anthony Campos gave Sockers a 3-1 lead.
A Juan Mancia penalty kick gave Dallas some hope in the final 10 minutes, but Ethan Otterberg put the result beyond doubt in the dying moments by slotting it home.
Atlanta United 1, Baltimore Armour 0
The Five Stripes broke down a brave defensive effort from the 10 men of Baltimore Armour with a wonderful late finish by Malachi Grant. Baltimore's starting goalkeeper, Jackson Boonmast, pulled out a string of impressive stops early before earning a 20th-minute red card for denial of an obvious goalscoring opportunity.
Joseph Yakim came into the game as the backup goalkeeper for Armour and carried on that form before conceding Atlanta's match-winner in the 88th minute.
St. Louis CITY SC 3, FC Boston Bolts 2
St. Louis CITY SC pulled off a gutsy comeback win in extra time after going two goals down inside the first 23 minutes. Leonardo Serodio and Timothy Shine gave the Bolts the lead.
However, Edin Prgo pulled a goal back for STL moments before a huge deflection carried in John DiMaria's equalizer. Mykhi Joyner would go on to complete the comeback in the 96th minute.
Total Futbol Academy 7, Cedar Stars Academy Monmouth 2
Total Futbol Academy put their regular-season struggles aside to win all three games in the MLS NEXT Flex tournament. They carried that momentum into a dominant win over Cedar Stars.
Javier Hernandez (2) and Jaziel Segura gave the California club a 3-0 halftime lead. A Nico Mastorakos double early in the second half seemed to settle the game, but the two sides traded four goals in the final 11 minutes to set up an exciting finish and a second-round game with Cedar Stars Academy's Bergen team.