Narayana Maharaj of Khedgaonbet.

Another devotee’s experience occurred long after Baba’s mahasamadhi (in
1918). Vinayak Daji Bhave, a clerk in the Railway Department, was anxious
to find a guru. So he undertook a devout daily reading of the “Guru gita”
which is said to be efficacious in such matters. After a month, he visited
a temple of Datta on a Thursday. But, to his wonder, there he saw a
samadhi (i.e. tomb of a saint) in the place of the usual idol of Datta!
Next morning he happened to see, for the first time, late Sri Dabholkar’s
(Hemadpanth) book on Sai Baba in which he saw a picture of Sai Baba’s
samadhi. At once he recognised it to be the one that he saw at the Datta
temple earlier and inferred that Sai Baba was his guru. For a time he took
Baba’s udi and read books on Baba. After some time the doubt cropped up in his mind that a tomb cannot be a substitute to a living guru who could
communicate with him. So again he did parayana of the Guru gita for a
week. Then the great saint Narayan Maharaj of Khedgaobet appeared in his
dream. Inferring that Narayana Maharaj was his guru, he went to
Khedgaonbet. There Sri Narayan Maharaj appeared in his dream and said, “I
and Sai Baba are not different from each other. Why do you not go there?”
Thus confirmed, Daji Bhave accepted Sai Baba as his guru. Later a sadhu
read his palm and said, “Sai Baba is your guru”. The appearance of Sai
Baba’s samadhi in the place of Lord Datta’s idol in the Datta temple and
its confirmation by Narayana Maharaj establish Baba’s identity with Lord
Dattatreya beyond any doubt.

Source: Sai Baba the Master by E.Bharadwaja