Pity Martinez scored the go-ahead goal in the 89th minute after being held out of coach Frank de Boer's starting lineup, and Atlanta United scraped out a 2-0 victory over visiting D.C. United on Sunday afternoon.

Josef Martinez added an insurance goal -- his 16th of the season -- in second-half stoppage time after missing an earlier penalty kick for Atlanta (11-8-3, 36 points), which moved above D.C. (9-6-8, 35 points) into second place in the Eastern Conference.

Pity Martinez provided the assist on that breakaway effort.

Brad Guzan made three saves to preserve his MLS-leading 10th shutout against a D.C. side that was at times surprisingly dangerous despite playing without star forward Wayne Rooney and conceding 71.4 percent of the possession.

Rooney was not on the roster after coach Ben Olsen permitted him to take the weekend off to recover from a range of minor injuries, according to a report from the Washington Post.

Atlanta signed Pity Martinez prior to the season from Argentine club River Plate for an MLS record transfer fee reported to be $14 million. But the reigning South American player of the year had only two goals and five assists in 20 games prior to Sunday, the second consecutive game in which de Boer relegated the attacking midfielder to the bench.

Martinez came on to replace Brandon Vazquez in the 65th minute, and finally got the game's crucial breakthrough 24 minutes later.

Midfielder Darlington Nagbe created the opportunity with his lofted pass from the right byline. Martinez drifted in front of goal, leaped and met Nagbe's cross at the top of the 6-yard box, heading it past goalkeeper Bill Hamid from close range.

Hamid had previously made four saves, including two impressive first-half stops on Josef Martinez to keep things even. And his refusal to bite on Josef Martinez's juke during a 72nd-minute penalty kick resulted in a spot kick that sailed well over the crossbar.

But the Atlanta United striker finally beat the D.C. goalkeeper after running onto Pity Martinez's through ball into a one-on-one, with little Hamid could do.