Prince made a surprise appearance last night at the intimate City Winery, going on stage at 1:45am.

The “Purple Rain” maestro joined his sometimes backing band New Power Generation, which is doing a residency — dubbed “Purple Week” — at the venue.

Twitter lit up when Prince played, with one fan posting, “Ninety minutes of Prince at City Winery tonight. Great set. Shorter than usual, but that new song ‘Big City’ was SO GOOD. VMAs weekend.”

Another added after the show, “Back from a secret Prince-New Power Generation reunion at City Winery. My funk levels have been recharged for the year. That man is God.”

The New Power Generation’s shows continue this week, including one after the MTV’s VMAs on Sunday night. Speculation is that Prince will be back as well.

He played City Winery’s Chicago location to test out new material in July.