Robinson wore his old No. 20 jersey and threw a strike to shortstop Ian Desmond, and the former Washington manager received a nice standing ovation from the sellout crowd.
Robinson felt honored that the Nationals asked him to throw out the first pitch.
"It was quite an honor," Robinson said. "I enjoyed doing it. I thank the Lerner family for asking me to do it."
Robinson then had a question-and-answer session with the fans at the Stars and Stripes Club, and he said afterward that he appreciated how much he meant to Nationals fans.
"It was a very nice moment, but the fans are ... one of the reasons it was so nice being here and managing here," Robinson said. "They were excited today, sure. But it was nice to hear them say the nice things they had to say. They deserve what's happening here today."
Robinson was the Nats' first manager, guiding them to a combined 152-172 record in 2005 and '06. His best season was in '05, when the club went 81-81 and was in the pennant race until the middle of September. Robinson also managed the Expos from '02-04, having a record above .500 in two of those three years.
"There were exciting times in the two years that we spent [in Washington], especially the first half of the first year," Robinson said. "It was great. It was exciting. It was good for the fans, because people said baseball wouldn't go here, with the Orioles just down the way. I told them they were wrong. They have great baseball fans here, and if you put a good product out there, they will come out and root for the team. It's great to see it, and it's well deserved."
Nationals manager Davey Johnson said it was great to see Robinson back at Nationals Park throwing out the first pitch. It also brought back memories to Johnson when the two played together with the Orioles in the 1960s and '70s. They won two World Series titles together, and Johnson credits Robinson for winning those titles in 1966 and '70.
"Frank is one of the greatest players I've ever been associated with," Johnson said. "When I think of Frank Robinson, I think of the first time I ever saw him. He came into Spring Training, and we had a game going on in Miami. ... He went and got his uniform on, had not had batting practice, and I remember it like it was yesterday, he hit one out of the ballpark. All of us turned to each other and said, 'We've got something here.' And, of course, he went on to win the Triple Crown.
"Robinson played the game hard, played the game right, and he was a big influence on me and the whole ballclub. We had a pretty good run with him there. I respect him and I think a lot of him. I think he's been just an outstanding example of a true professional."
Robinson gave Desmond his first chance make the team out of Spring Training in 2005. Desmond wears No. 20 in honor of the Hall of Famer.
"It's cool. It'll be fun to get to talk to him and poke at each other a little bit," Desmond said. "When he signed up [to manage the Nationals], he had this [throwing out the first pitch] in mind. I think he wanted to start something, and he did. He's got his stamp on this organization forever, and I'm forever indebted to him, and I think D.C. will be also."
Robinson is touched that Desmond wears the number in his honor.
"He has worn the number well," Robinson said. "I hope he has good luck with it for the future."
Robinson is not surprised to see the Nationals in the playoffs this year. It helps, according to Robinson, that the Nats built a strong farm system.
"[General manager Mike Rizzo] and his staff have done a tremendous job rebuilding the Minor League system and developing the young players and mixing them in with some veteran players," Robinson said. "The coaching staff has done an outstanding job. It came a little quicker than I thought it would, but after last year, I felt good about this franchise. I thought they would have an opportunity to something, if not this year, then next year. So it came a year sooner."