Johanna Konta beat fellow Briton Heather Watson in straight sets as the pair met for the first time on the WTA Tour at Indian Wells.
Konta, the British number one and 11th seed, moved into the third round of the BNP Paribas Open with a 6-4 6-4 win on Stadium 1.
Their only previous meeting came four years ago in a second-tier event in Barnstaple which saw Watson retire injured after losing the first four games.
This time it reached a proper conclusion and Konta, ranked 97 places above her opponent, made her quality tell despite some tough moments.
Watson won the first two games of the match and put together three in a row at the death as Konta threatened to wobble but there were too many mistakes of her own littered through the 94-minute match-up.
Watson double-faulted on nine occasions and at times grew visibly frustrated at her lack of control. In all she was broken on five occasions, edged out of the first set then faced with a foremidable 5-1 scoreline in the second.
The match appeared lost at that moment but Watson produced her best tennis of the day to take things deep, serving to love twice in a row and breaking in between.
The momentum finally gave way at the crucial moment and, following a good rally at match point, Watson failed to clear the net to settle matters in Konta's favour.
Karolina Pliskova breathed a sigh of relief after storming back to beat Olympic champion Monica Puig in the second round of the BNP Paribas Open.
Puig comfortably won the first set and looked like sending Pliskova packing before the third seed completed a hard-fought 1-6 6-4 6-4 victory.
Czech Republic's Pliskova will play Irina Camelia Begu in round three after the Romanian beat America's Louisa Chirico 6-1 7-5.
Dominika Cibulkova also survived a scare against world number 64 Jelena Ostapenko to secure her third-round place at Indian Wells in three sets.
Fifth seed Cibulkova was made to work by the Latvian but eventually triumphed 6-4 3-6 6-3 after a battle which lasted over two hours.
Russian Svetlana Kuznetsova, seeded eighth, had an easier evening in beating Sweden's Johanna Larsson 7-6 (7/3) 6-4.
Seventh seed Garbine Muguruza also impressed by winning 6-2 6-3 against Kirsten Flipkens and Kristyna Pliskova, twin sister of Karolina, overcame Daria Kasatkina 6-0 6-3.
Ukraine's Elina Svitolina, seeded 10th, fought back to win 3-6 6-3 7-6 (7/3) against China's Qiang Wang.
Kiki Bertens, seeded 18th, was a 6-2 6-2 winner against Belinda Bencic, 15th seed Timea Bacsinszky beat Monica Niculescu 7-5 6-2 while Kayla Day won 6-4 5-7 7-5 against Mirjana Lucic-Baroni.
There were also second-round wins for Daria Gavrilova, Roberta Vinci, Caroline Garcia, Anastasia Pavlyuchenkova and Barbora Strycova.