The NBC Nightly News anchor shared an adorable photo of himself holding the 10-month-old tyke in the newsroom.
"Look who just paid a surprise visit to his grandpa at work today. Not sure I’ll have the smile wiped off my face by air time! #ProudGrandude," Lester gushed in the caption.
Since then, Grandpa Lester has opened up about how wonderful it is to be a granddad.
"It is such a great feeling,” the newsman told "Tonight Show" host Jimmy Fallon in January.
He also admitted to Fallon that one of the best perks of being a grandparent is getting to love the sweet new bundle of joy without the sleepless nights so many new parents experience.
“Everything they say about being a grandparent is true," Lester said. "You get to experience the love, the joy and then, at the appropriate time, you (gestures) ‘Here you go,’ and get a full night’s sleep ... and not feel guilty about it."