The 100th edition of the Lamar Hunt US Open Cup kicked off by staying mostly true to form on Tuesday, with few upsets and most of the bigger names surviving the first round.

Of the three MLS teams with U-23s in the tournament, two - Seattle and Portland - advanced. The New York Red Bulls U-23s, meanwhile, were upended by the Ocean City Nor'easters.

An eye-opening upset came in the Battle for Arizona, as FC Tucson of the PDL toppled Phoenix FC of USL PRO. The other three USL PRO teams that took the field all advanced, though two needed penalties to punch their way through.

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Full list of results:

GPS Portland Phoenix (PDL) 2-0 Mass Premier Soccer (USASA)

Mass Premier Soccer (USASA) Brooklyn Italians (NPSL) 1-4 Icon FC (USASA)

Icon FC (USASA) Ocean City Nor'easters (PDL) 2-0 New York Red Bulls U-23s (NPSL)

New York Red Bulls U-23s (NPSL) Reading United AC (PDL) 2-0 FC Lehigh Valley United Sonic (NPSL)

FC Lehigh Valley United Sonic (NPSL) Red Force (USASA) 2-4 Ocala Stampede (PDL)

Ocala Stampede (PDL) Orlando City U-23s (PDL) 1(3)-1(5) VSI Tampa Bay FC (USL)

VSI Tampa Bay FC (USL) Carolina Dynamo (PDL) 4(4)-4(1) Chattanooga FC (NPSL)

Chattanooga FC (NPSL) Michigan Bucks (PDL) 0-2 Dearborn Stars (USASA)

Dearborn Stars (USASA) Pittsburgh Riverhounds (USL) 1(5)-1(4) RWB Adria (USASA)

RWB Adria (USASA) Dayton Dutch Lions (USL) 3-0 River City Rovers (PDL)

River City Rovers (PDL) Austin Aztex (PDL) 3-0 NTX Rayados (USASA)

NTX Rayados (USASA) PFC Tucson (PDL) 2-1 Phoenix FC (USL)

Phoenix FC (USL) Portland Timbers U-23s (PDL) 3-2 Sacramento Gold (NPSL)

Sacramento Gold (NPSL) Seattle Sounders U-23s (PDL) 5-1 Doxa Italia (USASA)

Doxa Italia (USASA) Laredo Heat SC (PDL) 2-0 PSA Elite (USASA)

PSA Elite (USASA) Georgia Revolution (NPSL) 4-3 Real Colorado Foxes (PDL)

Real Colorado Foxes (PDL) Ventura County Fusion (PDL) 3-2 FC Hasental (NPSAL)

The one game scheduled for Wednesday sees the Des Moines Menace (PDL) host the Madison 56ers (NPSL) at 8:30 pm ET.