Venus Williams advanced to round four in Indian Wells with a 6-2 7-5 Triumph over qualifier Christina McHale.
Even the 38-year-old, who overcome Petra Kvitova at the previous round after being fully a set and also a dual break down, lost the first match on serve after two double flaws.
She won the next five matches and took the set, afterward came from 3-1 down to wrap the game in one hour and 25 minutes when McHale double-faulted.
Williams will face world number 97 Mona Barthel, who overcome Julia Goerges.
Struff will play Milos Raonic at the fourth round, the Canadian fighting back from a set down in the decider to overcome American qualifier Marcos Giron 4-6 6-4 64.