Raducanu led 3-1 after a break in the first set, but her sixth double fault, which caused her to give the ball back on serve, drew groans from many of her fans at Melbourne Park.
It was worse to follow him.
Raducanu committed three more double faults in a bad ninth to put Alexandrova in front for the first time in the match at 5-4.
However, the Russian couldn’t serve and paid the price as Raducanu played a brilliant first tie-break.
Raducanu seemed to settle down in the second set, overcoming an early break to comfortably hold a 3-2 lead.
Then the double faults appeared again.
Three consecutive games in the sixth game built up the pressure, but Raducanu tried to save two break points before Alexandrova took her serve for 4-4.
After an unsuccessful serve attempt at 5-4, Raducanu defended the set in the 12th game with the first serve, after which Alexandrova – an aggressive attacking striker who showed her good side – hit a long backhand.
Raducanu dominated the overtime again, leading 6-0, and secured victory on her third match point after double-faulting in the first.
“That was the cherry on top,” Raducanu laughed.
Approaching tie-breaks, she added: “I think that’s one of my strengths.
“When those moments come where I hold on, I like to play into it.”
