The lefty was placed on the 15-day disabled list retroactive to March 21, due to back spasms.
"I feel great; everything felt good today," Pettitte said. "I got a lot of work in and was able to work on some stuff down the stretch."
Pettitte faced Triple-A Scranton/Wilkes-Barre, while fellow Yankee starter Ian Kennedy pitched to Double-A Trenton.
Pettitte said he warmed up about "five times" earlier on Sunday morning, and was confident in his six innings of work. He allowed one hit and one walk, striking out six.
When asked if he will be ready for April 5, when the Yankees play their fifth game and the first day Pettitte will be eligible to come off the DL, the veteran was confident.
"I'm all set," Pettitte said. "Did I have to get to 77 pitches today because I'm a little short [and] behind everybody? Yeah, but I'm ready for my start."
"Our plans right now, as of this minute, are to pitch Andy on Saturday," Yankees manager Joe Girardi said in New York. "Obviously, you wait to see how he wakes up tomorrow, but we have every expectation of pitching him on Saturday."
Kennedy threw 76 pitches on Sunday morning, and is on track to start the Yankees' fourth game on Friday.
Although Kennedy has been healthy, the Yankees wanted the right-hander to toss another game scenario to stay on the right timetable in the rotation. He tossed five innings on Sunday, fanning five and walking one.
Kennedy finished his spring campaign with a 2.00 ERA in 18 innings.
"I felt good," Kennedy said. "I felt really good after the first few pitches."
Brittany Ghiroli is an associate reporter for MLB.com. Bryan Hoch contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.