the oscillator index $i$. The random distribution of $\big\langle \phi_{i}(t)\big\rangle$ (Fig. \[fig3\](a)(i)) and $\big\langle \Omega_{i}(t)\big\rangle$ (Fig. \[fig3\](b)(i)) for $\varepsilon=0.0$ corresponds to the large difference in the initial frequency of the uncoupled oscillators due to the nonlinear parameter mismatch. The scenario of sequential phase synchronization to reach GPS can also be clearly visualized using the snap shots of the oscillators in the index vs index plot as shown in Fig. \[fig5\]. The diagonal line in Fig. \[fig5\](a) for $\varepsilon=0.0$ clearly shows the asynchronous evolution of all the oscillators in the array.

The phase locking of the first $14$ oscillators with the drive, forming the main cluster, for $\varepsilon=0.45$ is shown in Figs. \[fig3\](a)(ii) and  \[fig3\](b)(ii), while some of the other oscillators (oscillators with indices $22-24$, $35-36$ and $41-45$) away from it form phase synchronized clusters among themselves. The main cluster and other small clusters of phase synchronized oscillators are much more clearly visualized in Fig. \[fig5\](b) for the same coupling strength, in which oscillators with same frequency are assigned the same shape and color. The average phase and the average frequency for $\varepsilon=0.58$ depicted in Figs. \[fig3\](a)(iii) and Fig. \[fig3\](b)(iii) indicate that the first $26$ oscillators are synchronized with the drive 