First-place Minnesota United FC entered Saturday's match as the North American Soccer League's highest-scoring team and also had given up the fewest goals.

The defense did its job in a 1-0 victory against last-place Atlanta, but a lack of offensive punch concerned coach Manny Lagos. The Loons went ahead on Christian Ramirez's league-best 17th goal of the season, but the team could not extend its lead despite playing almost the final 30 minutes with a man advantage.

The victory, earned before an announced crowd of 5,744 at the National Sports Center Stadium in Blaine, pushed Minnesota's home unbeaten streak to 13 matches.

But Lagos said he noted a "lack of conviction" in allowing Atlanta (3-9-2) to hang around.

"At key moments we weren't quite pushing to say, 'I want to be in the spot to have the goal or finish the game off,' " Lagos said. "Without a doubt if there was ever a trap game this season, this was it."

Ramirez scored in the 58th minute on a rebound of Juliano Vicentini's shot. Ramirez drove the ball past the beaten goalkeeper and a flailing Silverbacks defender.

"I was just thinking, 'Technique, technique, technique,' because if I started celebrating early I was going to miss," Ramirez said. "It was a tough angle, so I was just trying to slow down and finish."

Ramirez (17 goals), Daniel Mendes (nine) and Miguel Ibarra (eight) have combined to score 34 goals. Going into Saturday, no other team in the league had scored more.

Minnesota (9-1-3) must find additional goal-scoring the next two games, however. Ibarra is expected to take part in a 10-day training camp with the U.S. men's national team. An official announcement from U.S. Soccer is expected Sunday.

Ibarra will become the first player from a second-tier league in North America to receive a call-up since 2005.

Ibarra, named NASL player of the month for September, was substituted out Saturday in the 72nd minute. His best scoring chance deflected off the goal post in the first half.

"He got to step off the field and physically and mentally get ready for that journey," Lagos said.

Minnesota's defense showed its depth against the Silverbacks. Woodbury native Brent Kallman played in place of central defender Tiago Calvano, who served a one-match suspension after drawing his fifth yellow card of the fall season last week at Ottawa.

"He showed he is a high-quality center back," Lagos said. "He hasn't gotten a lot of minutes, but he stepped in tonight and didn't miss a beat. He has a bright future for us."