A lone man waved from the lip of the dugout at Washington's new baseball field on Thursday, basking in the adulation of the 46,000 who had come to see him knock one out of the park.

But Pope Benedict carried a golden staff, not a maple bat.

Washington's new $611 million cathedral to baseball hosted rituals both sacred and secular on a beautiful spring day as the lowly Nationals team made way for the head of the world's largest Christian church.

"It kind of blesses the stadium. We're hoping the Nats win more games," said Judy Guy, of nearby Arlington, Virginia.

Like the sports fans who packed the park at its March 31 baseball opening, servicegoers praised the venue's sightlines and said it was a step up from Memorial Stadium in Baltimore, where Pope John Paul II held Mass in 1995.

"It's much more intimate and sacred," said Mary Ann Woltz of Selinsgrove, Pennsylvania, eating a hot dog while priests dispensed communion nearby.

The ballpark had undergone a quick make-over to tone down its commercial atmosphere.

A large papal seal covered home plate, and a gold and white altar sat in centre field. American flags covered the larger billboards, and video screens displayed papal symbols, not ads for beer and car insurance. The white-and-gold Vatican flag hung in a place of honour next to the US flag beyond the left-field seats.

And those sitting in the premier $300 seats behind home plate looked out at an infield filled with potted plants.

But the ballgame atmosphere was not completely absent.

The congregation drank Coke, munched on peanuts and applauded during spectacular moments. The scent of pizza wafted through the upper decks as Pope Benedict prepared communion.

Kids jumped up and down when their images appeared on the big video screen above centrefield, which also broadcast commentary after the service. Lines were long at souvenir stands that sold commemorative t-shirts, tote bags and baseball caps.

Pope Benedict will celebrate Mass on Sunday at Yankee Stadium in New York, home to one of baseball's most successful teams.

Locals said they didn't think the Pope's appearance would help the Nationals, who have lost 11 of 15 games so far this year and are languishing in last place.

"You probably won't see a crowd this size in the stadium any time soon," said Jamie Charles of Burke, Virginia.