WHEN Serena Williams let it slip recently that she intended to play a little less this year, her rivals probably breathed a sigh of relief.

After the 33-year-old extended her unbeaten run in 2015 by winning an eighth Miami title last night, they might be having a rethink.

The American's 6-2, 6-0 victory over Spain's Carla Suarez Navarro was as crushing as the scoreline suggests, her fifth straight victory over the world No 12 giving her a 66th career title.

The knee injury that caused her to pull out of the semi-finals in Indian Wells a fortnight ago is a thing of the past and Suarez Navarro was utterly helpless as she was wiped off the court in a barrage of winners.

At 2-2, 30-30 on the Williams serve in the first set, it looked as if it might be a contest but two aces dealt with that and from the moment she broke in the following game, the match was over.

Suarez Navarro, who possesses a single-handed backhand that is a joy to watch, is enjoying the best run of her career but Williams was far too powerful, smashing 17 winners to two in a first set that lasted just 32 minutes.

The second set was even faster as Williams, so relaxed that in the warm-up she decided to hit one-handed backhands instead of her normal two-hander, allowed her opponent only five points.

Another ripped forehand winner clinched victory and a simple fist pump in the direction of her family, friends and coaching support showed what everyone is beginning to realise: Williams is on a mission.

She is just the fourth woman in history to win a single event eight times or more, joining Martina Navratilova, Chris Evert and Steffi Graf. Her win in Melbourne at the start of the year moved her above Navratilova and Evert to 19 Grand Slam wins, three behind Graf in the all-time list.

It was fitting that it was Navratilova who presented her with her eighth trophy, although Williams will have to go some to catch her record of 12 straight wins in Chicago.

Williams will now switch speeds to clay and she will arrive in Paris just seven matches away from winning a second "Serena slam" of four consecutive Grand Slam tournaments.

If she manages that, it would be a brave person who bets against her completing the calendar Grand Slam this year either.