Three more goals from Josef Martinez set a new MLS record and lifted Atlanta United to a 3-1 victory over D.C. United on Saturday at Mercedes-Benz Stadium.

Martinez has a league-leading 22 goals this season, and the hat trick moved him atop the league’s career list in that category, with six. He accomplished the feat in only 42 games.

Atlanta United, which had an attendance of 45,087, leads MLS with 44 points. It improved to 7-2-3 at home this season. The team will play at Montreal on July 28.

There were metaphorical fireworks (remember: domed stadium) before the game when Atlanta United's starting 11 included Andrew Carleton making his first MLS start, and Ezequiel Barco, the most expensive transfer in MLS history, having his string of consecutive starts stopped at 15. He did not make the 18 for the first time since April 7. Speaking Thursday, Atlanta United manager Gerardo Martino didn't even hint that Barco, with four goals and one assist this season, wouldn't be available Saturday. Barco did train Thursday.

Carleton, 18, is a Powder Springs native and the first Homegrown signing in Atlanta United’s history. He has made four appearances this season as a reserve, with one assist.

Perhaps lost in the flurry of “Why” questions related to Barco being out and Carleton in was that Wayne Rooney made his first start for D.C. United. The former Manchester United standout made his first appearance off the bench in last week’s 3-1 win against Vancouver.

Rooney proved an immediate influence. His pass to Paul Arriola in the center of the field started a counterattack that Zoltan Stieber finished in the eighth minute to give D.C. United a 1-0 lead. It was a perfectly hit pass from Rooney, who drew several Atlanta United defenders toward him, into space for Arriola to run onto.

Atlanta United came close to tying the game in the 30th minute, but David Ousted came out of his goal to stop Martinez on a breakaway that was started after an excellent touch from Julian Gressel.

Martinez wouldn’t be stopped on his next attempt, putting his head on a cross from Hector Villalba to tie the score at 1-1 in the 30th minute. Martinez is the 21st player in league history to score at least 20 goals in a single season. It was Villalba’s fifth assist and Miguel Almiron’s 10th this season.

After Martino last week said that Martinez needed help in the penalty box, he had four teammates helping to occupy defenders on his goal.

Atlanta United took a 2-1 lead on another goal from Martinez, again scored on a header, in the 54th minute. Carleton’s pass into the penalty box was first hit by a D.C. United defender. The ball went right to Martinez for his seventh headed goal this season.

Martinez’s third goal was his easiest. He ran onto the ball near the top of the penalty box after a ball bounced off a D.C. United defender. Martinez needed only to round Ousted for the easy goal.