MIAMI -- Defending champion Serena Williams closed in on a seventh Sony Open title with a 6-2 6-2 quarter-final demolition of German Angelique Kerber on Tuesday, a win that came as the Crandon Park tennis facility was locked down due to a bomb scare.
Williams' win sets up a semi-final rematch of last year's final against Maria Sharapova, a five-time runnerup on the Miami hardcourts, who advanced with an equally impressive 7-5 6-1 win over eighth-seeded Czech Petra Kvitova.
While Williams was shutting down fifth-seed Kerber, Miami Dade police were locking down the sprawling tennis complex after a suspicious package was found at the main entrance.
Four lane traffic was halted in both directions in front of the complex while spectators were prevented from entering or leaving the facility.
"Yeah, there was a bomb threat and a lockdown but that's all I know about it. Scary," said Williams.
Sharapova and Williams, who have both achieved a career grand slam and held the number one ranking, were expected to develop into one of the great rivalries in women's tennis.
But it has not quite worked out that way with Williams dominating the series, winning 15-of-17 career meetings including the last 14.
The pair have clashed three times in Miami, Williams winning all three.
"It's no secret that she's been a big challenge of mine, an opponent that obviously I would love to beat," said Sharapova, who has not beaten Williams in almost a decade.
"There are certainly ways that I need to step up in certain situations that I haven't been able to do in the past against her.
"But it's great that I have come to that stage and have the opportunity to play her again."
Certainly Sharapova will have to be at her best as Williams' title defence has picked up steam with each match.
The world number one needed just 62 minutes to dispose of Kerber and has dropped one set on route to the final four.
"When you're playing champions, you have to play your best," said Williams, looking ahead to her meeting with Sharapova. "She always plays her best and her heart out against me.
"We just have to bring the best because we both are really good players. We just both do the best we can when we try to play each other.
"I love playing her. I really do."
Sharapova, who has come up short in the Miami final each of the last three years, dropped her opening serve to Kvitova but that would be the only time in the entire match.
The fourth-seeded Russian took control with a break to get back on level terms at 4-4 and then again to close out the first set. Sharapova then dominated the second set, storming through the first five games before a reeling Kvitova held her serve.
"I didn't have a good first few games, so I was happy that I was steady, that I kept trying to do the right thing, kept trying to be aggressive," said Sharapova. "I think that paid off as the match went on because I made a few too many unforced errors in the beginning."