This event occurs in the chapter entitled "December." Mrs. Baker is given some baseballs and mits from her brother-in-law to thank Holling and Danny for what happened after the Extravaganza. Dough and Holling are absolutely staggered to see that Joe Pepitone and Horace Clarke are there in the gym, two of the most famous Yankee players. They play ball for a while, but the tickets are mentioned at the end of this suprise session of baseball:
Afterward, they signed our baseballs and signed our mitts. They gave us each two tickets for Opening Day next April. And they gave Doug and Danny their caps.
Holling manages to gain tickets to the Opening Day at the Yankee stadium thanks to Mrs. Baker, who organises a meeting with two of the most famous players of the Yankee baseball team as a reward for Holling's exploits following the Extravaganza. This is of course the first of many signs that Mrs. Baker is an incredibly warm and empathetic human being, as Holling continues to realise.