A fighting century from opener Smriti Mandhana and a four-wicket haul from debutant Asha Shobana helped India to a 143-run win over South Africa in the first match of their ODI series in Bengaluru on Sunday.

After winning the toss and opting to bat first, Mandhana's innings of 117 off 127 balls – her sixth ODI hundred – helped India to a competitive total after struggling at 99/5 in 21.5 overs.

Despite the challenging pitch conditions that saw top-order of Shafali Verma (7), captain Harmanpreet Kaur (10), and Jemimah Rodrigues (17) falter, Mandhana exhibited composure and adapted her game accordingly.

Mandhana first partnered with Deepti Sharma (37 off 48 balls), adding 81 runs for the sixth wicket to stabilise India's innings.

Later the southpaw added 58-runs for the seventh wicket alongside Pooja Vastrakar, who finished with an unbeaten 31.

Asked to chase 266 for a win, the South African batters never got going and were bowled out for just 122 in 37.4 overs.

Pacer Renuka Thakur started the proceedings for India with the ball, scalping the dangerous Laura Wolvaardt in the very first over for just four, while Vastrakar removed Anneke Bosch from the other end in the sixth over.

South Africa laboured to 33/2 in ten overs before the Indian spinners took over and dried up the run flow and kept striking at regular intervals.

Deepti Sharma finished with figures of 2-10 in six overs, while Shobana finished with 4-21 in 8.4 overs as India took an 1-0 lead in the three-match ODI series.