LONDON (REUTERS) - Top seed Angelique Kerber was knocked out in the last 16 of Wimbledon by Garbine Muguruza on Monday, ensuring she will lose her world No. 1 ranking.
Muguruza's 4-6, 6-4, 6-4 victory marked the ninth consecutive time Kerber has failed to beat a top-20 opponent. The German last achieved that feat in 2016 and she has now been beaten by the Spaniard in five straight matches.
Romanian Simona Halep could take the top ranking, if she can reach the semi-finals. She beat Victoria Azarenka 7-6 (7-3), 6-2 and will play Johanna Konta, who became the first British woman to reach the quarter-finals since Jo Durie in 1984, when she beat Caroline Garcia of France 7-6 (7-3), 4-6, 6-4
Should Halep fail to advance to the semis, then Czech Karolina Pliskova will take over at the summit when next week's rankings are announced.
But there was a bitter irony for Kerber who, despite being somewhat hampered by her left knee, produced her best display in months yet bids farewell to Wimbledon and her status as the world's best.
On Centre Court, experience triumphed over youth, as Venus Williams downed Croatian teenager Ana Konjuh 6-3 6-2 in a fourth-round battle of the baseliners.
Facing each other across the net for the first time, the oldest and youngest players left in the singles draw slugged it out in a quickfire contest that was littered with as many unforced errors as clean winners.
The Kerber-Muguruza match was always destined to be close, pitting the 2016 runner-up against her 2015 equivalent and there was little to choose between the pair in what was a high quality contest on Court Two.
Kerber broke to go 5-4 up in the first set, when at the end of a fierce rally her Spanish opponent went wide and allowed the German to serve out, securing the set with an emphatic smash.
The second set was on-serve until, with Kerber serving at 5-4 down, the tall Muguruza, who had saved three break points in the set, broke to secure it with a fine cross-court winner.
It was just reward for Muguruza's attacking and positive play and was warmly appreciated by temporary coach Conchita Martinez, Wimbledon champion in 1994.
Kerber's left knee, which she appeared to hurt in the first set, was reducing her push-off on serve with the consequent impact on her speed but the third set became a battle of nerves and stamina in the early afternoon heat.
The German broke in the first game and led 2-0 but both were struggling to hold serve and it was soon 3-3 with two breaks each.
In an epic 10-minute game, Muguruza held for 4-3 with the crowd appreciating some hugely entertaining rallies between the determined pair.
Two games later, Kerber dealt with two match-point threats, but Muguruza grabbed the third to book her place in the last eight.
The Spaniard will next face Russia's Svetlana Kuznetsova after the seventh seed beat Agnieszka Radwanska 6-2, 6-4 in the last 16.
Konta had previously won only one match in five Wimbledon appearances but now suddenly finds herself with a realistic chance of winning it and becoming the first home champion since Virginia Wade 40 years ago.
The seventh seed, who spent her formative years in Australia before moving to play in Spain as a 14-year-old and then becoming British in 2012, delivered an efficient display in an even battle, albeit with a major wobble in the middle, to overcome a tenacious opponent.
Konta was always on top in the first set despite having to take it via a tie-break but then lost five games in a row en route to losing the second. Serve dominated the final set so much that the first break point did not arrive until the 10th game, but when it did, Konta took full advantage as Garcia netted to lose the match.
As for Williams, seeded 10th, she made her debut in the grass-court Grand Slam back in 1997. That was several months before the birth of her 27th-seeded opponent, who was appearing in the fourth round at the All England Club for the first time.
After a scrappy opening set, the 37-year-old began finding her range on ground strokes, keeping her younger opponent pegged at the back of the court.
Konjuh saved three match points on serve but succumbed in the following game when she hit a backhand long.
Williams becomes the oldest player since then 37-year-old Martina Navratilova in 1994 to reach the quarter-finals, where she will face the brightest of the sport's next-generation stars, French Open champion Jelena Ostapenko.