British interest in the Miami Open is over before the quarter-finals - the first time that has happened since 2011 - after a physically restricted Johanna Konta was outlasted on Monday by the evergreen Venus Williams.
American Williams defeated 26-year-old Kiki Bertens, of the Netherlands, after saving three match points.
Meanwhile former world number one Kerber was made to sweat in her gruelling clash with China s Wang Yafan before prevailing 6-7 (1/7), 7-6 (7/5), 6-3.
Konta had finished the first set strongly, firing a pair of backhand winners to close it out, but then dropped her serve early in the second set and found herself pushed back by a ferocious Williams bombardment.
After holding to love, the Brit continued to turn the screw, creating four break point chances in a marathon third game, but the experienced American held firm to get on the board.
A sultry late afternoon on Key Biscayne was a different environment to their meeting at SW19, which saw Williams emerge an eventually comfortable victor for the loss of six games after Konta had spurned a few opportunities in the first set.More news: Pittsburgh hiring Duke associate head coach Jeff Capel
Just when the erratic Konta needed to put her foot on the accelerator, it was William who responded superbly to put her opponent firmly on the backfoot.
"It didn't look good sometimes but that's why you play to the last point".
Fourth seed Elina Svitolina of Ukraine also advanced with a 7-5 6-4 win over Australian Ashleigh Barty, as did Czech Republic's fifth seed Karolina Pliskova after Zarina Diyas of Kazakhstan retired hurt while trailing 6-2 2-1. She hit just one victor in the second set as the American began to dominate and send the encounter into a decider which began with Konta receiving lengthy treatment for a back problem.
Williams faced more breakpoints in the third although this time the danger was averted, thanks to some powerful serves. She fell behind 0-2 in the tiebreaker before winning seven straight points for the victory.
But US Open champion Stephens dominated Spain's reigning Wimbledon champion to record a 6-3 6-4 win and advance to the quarter-finals where she will face Germany's Angelique Kerber for a place in the semi-finals.
American Stephens - seeded 13th - wrapped up a 6-3 6-4 victory in one hour and 28 minutes.