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The old open cluster M67, populated with blue straggler stars (BSSs), is awell known test bed to study the BSS formation pathways. Here, we report thefirst direct detection of a white dwarf (WD) companion to a BSS in M67, usingfar-UV images from the \textit{Ultra Violet Imaging telescope} ({\it UVIT}) on{\it ASTROSAT}. Near-simultaneous observations in three far-UV bands combinedwith {\it GALEX}, {\it IUE}, ground and space based photometric data covering0.14 -11.5 $\mu$m range for WOCS1007 were found to require a binary fit to itsspectral energy distribution (SED), consisting of a BSS and a hot companion. Onthe other hand, a single spectral fit was found to be satisfactory for the SEDsof two other BSSs, WOCS1006 and WOCS2011, with the latter showing a deficientfar-UV flux. The hot companion of WOCS1007 is found to have a T$_{eff}$ $\sim$13250-13750K and a radius of 0.09$\pm$0.01 R$_\odot$. A comparison with WDmodels suggests it to be a low mass WD ($\sim$ 0.18$M_\odot$), in agreementwith the kinematic mass from the literature. As a low mass WD ($<$0.4$M_\odot$) necessitates formation through mass transfer (MT) in closebinaries, WOCS1007 with a known period of 4.2 days along with its fastrotation, is likely to be formed by a case A or case B binary evolution.

UVIT Open Cluster Study. I. Detection of a White Dwarf Companion to a Blue Straggler in M67: Evidence of Formation through Mass Transfer