Nadal now holds a 9-0 career record over Stanislas Wawrinka, after a 6-2, 6-4 win.
The title is Serena Williams' 50th of her singles career and extends her amazing run over Sharapova who she hasn't lost to in 12 meetings since 2004.
Of the three leading seeds at the event, which begins on Sunday at the picturesque Foro Italico, only number three Murray lasted until the quarter-finals in Madrid last week.
World number 113 Andujar was blown away by compatriot Nadal 6-0, 6-4 on Saturday.
Sharapova will compete in her first Madrid final after beating Serbian Ana Ivanovic 6-4, 6-3 while Williams sealed her place as she overcame seventh seed Sara Errani 7-5, 6-2 on Saturday.
Serena Williams was also happier with her performance against Sara Errani in the semis than the error-strewn display she produced against Spanish wildcard Anabel Medina Garrigues in the quarter-finals.
An off-colour Indian team squandered all the six points it earned in the second set to suffer a 2-6 4-6 defeat against the French-Polish combo in the quarter-finals of the euro 4,303,867 clay court tournament.
Ferrer is currently ahead of the 11-time Grand Slam champion in the world rankings due to Nadal's seventh month layoff in the second-half of last season.
Despite losing the second set 0-6, Serena Williams withstood a sterling effort from 30-year-old wildcard Anabel Medina Garrigues to book her place in the Madrid Open semi-finals.
Leander and Melzer were off-colour today as Haas-Stepanek pair broke their service on four occasions which was testimony to the supremacy of the German-Czech duo.
Federer was competing for the first time since a two-month break from the tour and he admitted that he needs more practice before heading to the Rome Masters next week and eventually onto the French Open at the end of the month.
The 26-year-old Nadal now stands at 28-2 on the season as he looks to reach his seventh final since his comeback from a seven-month injury lay-off in February.
World No.2 Maria Sharapova, who has yet to drop a set, continued her stroll into the quarter-finals as she overcame Sabine Lisicki 6-2, 7-5.
Japan's world number 14 Kei Nishikori dumped defending champion Roger Federer out of the Madrid Masters at the third round stage on Thursday as he beat the 17-time Grand Slam champion 6-4, 1-6, 6-3.
The Russian former No. 1 will face either Daniela Hantuchova or Kaia Kanepi next.
The fifth seed Indo-American pair lost 5-7 1-6 to the unseeded Russian-Czech pair in one hour and 10 minutes in the second round of the euro 4,033,254 clay court event.
Earlier, last year's finalist and sixth seed Tomas Berdych stayed on course for a quarter-final meeting with Andy Murray as he recovered from a set down against Jerzy Janowicz to win 6-7, 6-3, 6-2.
Djokovic - who ended Rafael Nadal's eight-year winning streak at the Monte Carlo Masters last month - said the loss had more to do with poor preparations than an injury.