Roger Federer played superbly to claim a third straight win over Rafael Nadal for the first time in his career and reach the last eight in Indian Wells.
The Swiss, 35, won 6-2 6-3 to follow up his Australian Open final victory over the Spaniard two months ago, when Federer won his 18th Grand Slam title.
He will next face Australia's Nick Kyrgios, who upset world number two Novak Djokovic 6-4 7-6 (7-3).
Svetlana Kuznetsova was the first player into the women's semis.
The eighth seed saw off fellow Russian Anastasia Pavlyuchenkova 6-3 6-2 and next meets Czech third seed Karolina Pliskova or Spaniard Garbine Muguruza, seeded seventh.