MELBOURNE (Reuters) - Defending champion Roger Federer remains on track for a 20th grand slam title after beating Czech Tomas Berdych 7-6(1) 6-3 6-4 to advance to the Australian Open semi-finals on Wednesday.
Second seed Federer opted for an aggressive approach for most of the encounter, smashing 61 winners and grabbing 23 points at the net.
The 36-year-old Swiss player recorded his eighth win in 10 grand slam meetings against Berdych to set up a clash with South Korea's Chung Hyeon on Friday.
The 21-year-old, who ousted six-time champion Novak Djokovic in the fourth round, continued his blazing run with a 6-4 7-6(5) 6-3 win over American Tennys Sandgren.
"I'm very excited to play Chung, I thought he played an incredible match against Novak (Djokovic)," Federer said in his on-court interview.
"Right now I couldn't tell you how I need to play him. One thing I know is I'm going to be playing aggressive."
Chung, ranked 58 in the world, became his nation's first grand slam semi-finalist and the lowest ranked player to reach the last four at Melbourne Park since Marat Safin in 2004.
In the women's field, world number one Simona Halep produced a sublime display to oust sixth seed Karolina Pliskova of Czech Republic 6-3 6-2 in the quarter-finals.
Halep came back from an initial 3-0 deficit in the opening set, running off on a nine-game winning streak at one point to wrap up the match in just over an hour.
"For sure it wasn't my best start," Halep said after the match. "I just knew that I had to restart, actually, after three games -- just to stop missing that much and to move better."
Halep's first semi-final appearance in Melbourne will be against 2016 champion Angelique Kerber, who defeated American Madison Keys 6-1 6-2 in the quarter-finals.
Highlights of Wednesday's 10th day of the Australian Open, the first grand slam tournament of the year (times in GMT):
1050 FEDERER THROUGH TO SEMI-FINAL
Defending champion Roger Federer reached his 14th semi-final at the Australian Open with a 7-6(1) 6-3 6-4 victory over Czech Tomas Berdych.
The 36-year-old Swiss is yet to drop a set this year at Melbourne Park.
0614 HALEP STORMS INTO SEMI-FINALS
Top seed and world number one Simona Halep moved a step closer to a maiden grand slam title with an emphatic 6-3 6-2 win over Czech Karolina Pliskova to set up a semi-final date with Angelique Kerber.
"She is moving well and returning the ball good in the court," Halep said of Kerber. "I have to be strong in my legs and be calm. To start playing like I did at the end of the match and dominate the match and finish the points."
0435 CHUNG MASTERS TENNYS TO REACH SEMI-FINALS
Chung Hyeon became the first South Korean to reach the semi-finals of a grand slam when he beat American Tennys Sandgren 6-4 7-6(5) 6-3 in two hours and 28 minutes on Rod Laver Arena.
The bespectacled 21-year-old sealed victory when Sandgren went long after an extraordinary final game and will face reigning champion Roger Federer or Tomas Berdych in the last four.
0330 MADISON KEYS ON HER QUARTER-FINAL LOSS
"Sometimes you just don't play very well out there."
0215 FALSE ALARM ON ROD LAVER ARENA
The quarter-final between Tennys Sandgren and Chung Hyeon was disrupted early in the first set by an alarm broadcasting "Evacuate! Evacuate! Evacuate!" over the public address system.
The players returned to their chairs while umpire James Keothavong investigated and the match resumed after he had confirmed it was a false alarm.
0105 KERBER CRUSHES KEYS TO REACH SEMI-FINALS
Revitalised 2016 champion Angelique Kerber made a major statement of intent as she stormed into the semi-finals with a dominant 6-1 6-2 victory over Madison Keys.
"I'm really enjoying my tennis right now. I enjoy being on court, right now," the German said.
"I'm just happy to get through and be here in the semis."
0015 PLAY UNDERWAY WITH KERBER AND KEYS CLASH
Play got underway on schedule at 11 a.m. local time (0000 GMT) at Melbourne Park with Angelique Kerber and Madison Keys on Rod Laver Arena in the women's quarter-finals.
The temperature was 21 degrees Celsius (69 degrees Fahrenheit) and forecast to reach a high of 24.
(Compiled by Nick Mulvenney and Hardik Vyas; Editing by Greg Stutchbury/John O'Brien/Christian Radnedge/Alexander Smith)
