D.C. United's Collin Martin (black jersey) eludes Arabe Unido goalkeeper Miguel Lloyd during their Scotiabank CONCACAF Champions League match in Washington, D.C., on September 15, 2015. (Photo: Linda Cuttone/Sports Vue Images)

WASHINGTON, D.C., USA -- D.C. United is through to the knockout stages of the Scotiabank CONCACAF Champions League (SCCL) for a second straight year thanks to a 2-0 win over visiting Arabe Unido on Tuesday at Robert F. Kennedy Stadium.

Conor Doyle scored in the opening minute for the Major League Soccer side, which has won seven straight #SCCL group-stage matches.

Jared Jeffrey also scored before halftime in a victory that ensures D.C. (3W-0D-0L, 9 points) will be playing only for quarterfinal seeding in next week’s trip to face Montego Bay United (0W-0D-2L, 0 points) in Jamaica.

The defeat eliminated Arabe Unido (1W-0D-2L, 3 points) from contention as its record against U.S.-based teams in the competition fell to 1W-1D-6L.

Scarcely 30 seconds passed before Conor Doyle ensured that D.C. would score in its 18th consecutive SCCL contest. Chris Pontius started the move with a cross from the left that buzzed slightly behind intended target Jairo Arrieta. Doyle reached the ball on the right side of the penalty area and drove a low, firm finish toward the far post beyond goalkeeper Miguel Lloyd.

Jeffrey made it 2-0 in the 22nd minute off a corner kick that D.C. won when Pontius’ cross was redirected over the crossbar.

Facundo Coria delivered an in-swinging ball that reached Jeffrey unmarked at the back post. The 25-year-old midfielder nodded a simple header into the goal from close range.

Needing maximum points to prolong its quarterfinal hopes, Arabe Unido kept pressing and nearly broke through on a few occasions.

In the 52nd minute, Renan Addles’ ferocious 35-yard free kick rattled goalkeeper Andrew Dykstra’s crossbar. Seven minutes later, Abdiel Macea reached a loose ball inside the 6-yard box, but could only poke it onto the left post.

D.C. will face host Montego Bay next Tuesday, while Arabe Unido closes group play against the Jamaicans on October 22.