HIGHLIGHTS-Tennis-Day four at the Australian Open

MELBOURNE, Jan 19 (Reuters) - Latest news from the fourth day of the Australian Open tennis championships on Thursday (all times GMT): 1315 NADAL COMFORTABLY THROUGH TO THIRD ROUND Spanish ninth seed Rafael Nadal secures a routine 6-3 6-1 6-3 win over 2006 runner-up Marcos Baghdatis to advance to the third round, where he will face 19-year-old German Alexander Zverev. 1229 THIEM FIGHTS OFF THOMPSON TO ADVANCE Eighth seed Dominic Thiem overcame some stiff resistance from Jordan Thompson before he sealed a 6-2 6-1 6-7(6) 6-4 victory over his Australian opponent. The Austrian faces France's Benoit Paire next. 1130 SERENA USES SOCIAL MEDIA TO MAKE HER VOICE HEARD "I think it's not only enjoyable, but I think it's a good opportunity to most importantly stand up for social issues and things that I find important," the 22-times grand slam champion said after her win over Czech Republic's Lucie Safarova. READ MORE Djokovic's record title bid ends in second round Nadal smashes through Baghdatis to reach third round Federer to face Berdych early for first time in nine years Serena steamrolls Safarova to reach third round Radwanska dumped out of Australian Open second round Djokovic blames bad day at office for Istomin shocker Match stats: Istomin v Djokovic at Australian Open Defending champion Djokovic knocked out of Australian Open Konta hones mental mettle to down Osaka Blink and it's over as Pliskova warns rivals Raonic races into third round 'Nick off!' - Australian media slam Kyrgios Murray moving well after ankle injury scare 1027 SERENA STORMS THROUGH TO THIRD ROUND American second seed Serena Williams has no problems against Lucie Safarova, beating the Czech 6-3 6-4. Williams will face compatriot Nicole Gibbs in the third round. 1011 ISTOMIN CREDITS MOTHER FOR BELIEVING IN HIM AFTER 2001 CAR ACCIDENT "He (the doctor) didn't say that, I never play, but he didn't think I was going to start playing again. "It was bad accident. But thanks to my mother, she was always believing in me. She (was) always saying, just keep going." 0918 Lucic-Baroni upsets Radwanska to progress Croatia's Mirjana Lucic-Baroni made quick work of Agnieszka Radwanska, beating the Polish third seed 6-3 6-2 in 62 minutes. 0845 DJOKOVIC PLAYS DOWN SURPRISE LOSS TO ISTOMIN "I don't think it was physical. We both looked okay. After four-and-a-half hours, we didn't seem to be tired. Of course, four-and-a-half hours is not easy on the body," Novak Djokovic said after his loss to Uzbek Denis Istomin. "But still, I don't think that has affected neither me or my opponent. It was just in the game of tennis, one guy beats the other guy. That's all I can say." 0820 DEFENDING CHAMPION DJOKOVIC KNOCKED OUT BY ISTOMIN Istomin causes a massive upset as he beats defending champion and second seed Djokovic 7-6(8) 5-7 2-6 7-6(5) 6-4 in four hours and 48 minutes. Istomin faces Spanish 30th seed Pablo Carreno Busta in the next round. 0745 ROARING RAONIC LOOKS AT THE SMALL DETAILS "In general over the last probably three-four tournaments, I've tried always to be a bit more positive and vocal with myself. I don't know how much of that I had in me," he said after his win over Luxembourg's Gilles Muller. "I just try to do these little things to get a better level of tennis out of myself." 0726 KARLOVIC COMFORTABLY THROUGH TO THIRD ROUND Big-serving Croatian Ivo Karlovic secures a routine 6-4 6-4 6-4 win over Australia's Andrew Whittington to advance to the third round, where he will face Belgium's 11th seed David Goffin. 0658 MONFILS FIGHTS OFF DOLGOPOLOV TO ADVANCE Sixth seed Gael Monfils overcame stiff resistance from Alexandr Dolgopolov before sealing a 6-3 6-4 1-6 6-0 victory against the Ukrainian. 0634 GOFFIN STORMS THROUGH TO THIRD ROUND Belgium's 11th seed David Goffin has no problems against a sloppy Radek Stepanek, who committed 44 unforced errors, beating the 38-year-old Czech 6-4 6-0 6-3. 0545 RAONIC BEATS MULLER, FACES SIMON IN THIRD ROUND Canadian third seed Raonic, with 21 aces and 56 winners, beats Luxembourg's Muller, beating the 33-year-old 6-3 6-4 7-6(4). The big-serving Raonic faces French 25th seed Gilles Simon in the next round. 0520 FERRER REACHES THIRD ROUND David Ferrer rallies from a set down to beat American Ernesto Escobedo 2-6 6-4 6-4 6-2. The Spanish 21st seed faces compatriot Roberto Bautista Agut in the next round. (Compiled by Greg Stutchbury and Shravanth Vijayakumar; Editing by John O'Brien/Sudipto Ganguly/Pritha Sarkar)