Sanders also renewed his attacks on Buttigieg from earlier in the week, raising news reports of Buttigieg raising campaign funds from big money interests on Wall Street.
That was also turned into a Twitter video attack on Saturday evening as well.
While Sanders drew 1100 people to his largest event of the day at the Rochester Opera House, Buttigieg drew 975 in Keene, not far from the border of Sanders' home state of Vermont.
"Our numbers at our events have grown a little bit," Buttigieg said with a smile.
The South Bend, Indiana mayor was introduced by a special guest, actor Michael J. Fox, who delighted the crowd with several riffs on the current state of the race for President.
"We have a very stable Rhodes scholar," Fox said to laughter, mimicking the President's line about how he considers himself a 'very stable genius.'
Fox then turned to the President's middle initial, Donald J. Trump.
"The 'J' stands for genius," Fox said to the delight of the crowd, as he gave his star backing to Buttigieg, who also raised the specter of a second term for Mr. Trump.
"I am the candidate best prepared to defeat Donald Trump," Buttigieg declared.
Sanders has events on Sunday scheduled in Plymouth, Hanover, Claremont and Keene.
Buttigieg will be in Nashua, Dover, Salem and Londonderry.