Emma Raducanu put in an impressive showing as she beat Beatriz Haddad Maia 6-1 2-6 6-4 in their third-round match at Indian Wells.
Raducanu dropped her serve twice as her Brazilian rival then levelled.
In the decider, Raducanu produced some brilliant tennis and broke Haddad Maia in the seventh game before keeping her nerve to serve out for the match.
Raducanu, who is 77 in the women's rankings, will play world number one Iga Swiatek or Bianca Andreescu in the last 16.
More to follow.