Federer has been brandishing an aggressive style of play, forcing the action and rushing in to half-volley weak second serves to forge an advantage.
It was Kristyna's first win over a top-five ranked player and she will go on to play fellow Czech Barbora Strycova in the quarter-finals.
World number one Naomi Osaka was beaten in her opening match at the Dubai Duty Free Tennis Championships on Tuesday, losing to France's Kristina Mladenovic 6-3, 6-3 on her return to competitive action after winning last month's Australian Open.
Summary of sports events and persons who made news on Tuesday
Images from matches played on Day 4 of the Australian Open at Melbourne Park on Thursday
Osaka survives test to reach last 16
PHOTOS from day three of the Wimbledon championships at the All England Lawn Tennis and Croquet Club in London on Wednesday.
Images from Day 2 of the Australian Open in Melbourne on Tuesday
Defending champion Djokovic fired his 15th ace on match point to defeat Querrey but his serve had been an issue earlier in their second-round encounter.
Playing tennis professionally can be difficult physically, mentally and emotionally. But the tennis courts have often been the venue for for blossoming romance as love-struck couples decide it is game, set and match.
Ferrer, 37, announced earlier in the year he would end his 19-year career at the Madrid Open and prolonged his time on court by a day by beating Roberto Bautista Agut on Tuesday, but was easily overpowered by world number four Zverev.
Form guide for American Serena Williams ahead of Thursday's US Open semi-final clash against Latvia's Anastasija Sevastova:
Home favourite Kei Nishikori defeated Frenchman Richard Gasquet 7-6(2), 6-1 in the semi-finals of the Japan Open on Saturday, setting up a final against Russian qualifier Daniil Medvedev.
Round-up of the Rolland Garros tournament being played in Paris.
Angelique Kerber, who will reclaim the world number one ranking on Monday, breezed to a 6-2, 6-1 second-round victory over fellow German Andrea Petkovic at the BNP Paribas Open on Saturday.
Rafael Nadal gave a much improved performance to advance into the quarter-finals of the Barcelona Open on Thursday, dispatching Spanish compatriot and crowd favourite David Ferrer 6-3, 6-3.
The British number one will play Croatian Donna Vekic, 7-6(5), 3-6, 7-6(4) victor over Czech Lucie Safarova in the day's second semi-final, in the climax to the Wimbledon warm-up tournament on Sunday.
The match ended in 52 minutes as Williams played her forehand into the net.
Big-serving Isner reaches Montreal second round
Milos Raonic overcame third seed Grigor Dimitrov 7-5, 3-6, 6-3 to reach the third round at the Madrid Open on Tuesday and set up an all-Canadian clash with teenager Denis Shapovalov.
It was the Russian's first competitive match since she withdrew from the St Petersburg Open in January.
World number two Rafael Nadal dropped a set at the Barcelona Open for the first time in four years before advancing to the last 16, beating Argentine Leonardo Mayer 6-7(7), 6-4, 6-2 on Wednesday.
Rafael Nadal extended his astonishing winning run on clay to 42 consecutive sets as he reached the semi-finals of the Barcelona Open with a 6-0, 7-5 victory over Slovakia's Martin Klizan on Friday. The defending champion will face David Goffin on Saturday after the Belgian beat Spaniard Roberto Bautista 6-7(3), 6-2, 6-2.
Images from all the action on Day 4 of the Australian Open in Melbourne on Thursday
Top seeded Ash Barty overcame a slow start to defeat Maria Sharapova 6-4 6-1, while Simona Halep battled past Ekaterina Alexandrova 3-6 7-5 6-4 in the second round of the Cincinnati Masters on Wednesday.
Nadal, playing his first match since losing to Roger Federer in the Wimbledon semi-finals, fell behind 5-2 in the tiebreak before roaring back to prevail in his first career meeting with world number 53 Evans.
Frenchman Benoit lost his temper in the third game of the second set when top seed Tsitsipas halted the match to attend to a broken shoe lace.
The Russian five-times Grand Slam champion struggled for rhythm initially on the low-bouncing grasscourt at the Mallorca Open but picked up the pace to beat Viktoria Kuzmova 7-6(8), 6-0.
IMAGES from Day 8 of the matches played at the US Open at Flushing Meadows on Monday
Images from Day 6 of the US Open in New York, on Saturday.
Images from Day 3 of the French Open matches played at Roland Garros on Tuesday
Garbine Muguruza's preparations for next week's Australian Open were thrown into disarray when the world number three pulled out of the Sydney International with a thigh injury on Wednesday.
IMAGES from Day 7 at Wimbledon on Monday
5 exceptional players who surprised us at Melbourne.
Roger Federer rallied from a set down to beat Moldovan surprise package Radu Albot 4-6, 7-5, 6-3 in a stuttering start to the 20-times Grand Slam champion's Miami Open campaign on Saturday.
Images from Day 4 of the Australian Open in Melbourne on Thursday.
Images from Day 3 of the French Open in Paris on Tuesday
Defending champion Naomi Osaka of Japan was upset 7-5, 6-4 by Belinda Bencic in the fourth round at the US Open on Monday as the Swiss reached the quarter-finals for the second time.
IMAGES from the Australian Open matches played at Melbourne Park on Wednesday
The returning Scot also announced his withdrawal from next week's Rogers Cup in Toronto.