Miami - World number one Novak Djokovic was struggling to play his best, but held firm when pressed to the brink on Tuesday and battled into the ATP and WTA Miami Open quarter-finals.
The two-time defending champion outdueled Austrian 14th seed Dominic Thiem 6-3, 6-4, stretching his Miami win streak to 13 matches to book a last-eight date on Wednesday against Czech seventh seed Tomas Berdych.
"Straight set win but far from easy. It was a tough match," Djokovic said. "I kept my serves. But I made a lot of double faults and he had me under a lot of pressure."
Djokovic, a five-time Miami winner overall, rescued 13 of 14 break points, four of them in the last game of the first set and four more in a dramatic 14-minute final game before hitting a forehand winner on his fourth match-point opportunity.
"I had some luck in that last game where he missed a couple of easy forehands to get the break back and get into the match," Djokovic said. "I stayed tough when it was most needed. The important moments I tried to make him play, make him run."
Djokovic won his 11th Grand Slam title two months ago at the Australian Open and has also lifted Doha and Indian Wells trophies this year while Thiem captured titles last month at Acapulco and Buenos Aires.
The 28-year-old Serbian made eight double faults and 29 unforced errors against only two aces and eight winners.
"The second serve was not working that well. That was due to the pressure he was imposing. I just didn't have the rhythm," Djokovic said.
"Generally I don't get to face that many break points. I'll try not to get myself in those positions as much."
Berdych outlasted French 10th seed Richard Gasquet 6-4, 3-6, 7-5, but has won only two of 24 meetings with Djokovic, having lost their past nine matches since a 2013 Rome quarter-final victory.
They are the only top-10 men still playing except for Japanese sixth seed Kei Nishikori, who meets Spanish 17th seed Roberto Bautista Agut in a later match.
Only one of the top 12 women remains after Romanian fifth seed Simona Halep was ousted 4-6, 6-3, 6-2 by 19th-ranked Swiss Timea Bacsinszky, who advanced to a semi-final against the winner of a later match between Russians Svetlana Kuznetsova and Ekaterina Makarova.
"To beat someone who fights as hard as she does, it's something amazing," Bacsinszky said. "I'm happy with it."
Bacsinszky's "lucky charm" and friend, Swiss women's world overall Alpine ski champion Lara Gut, was in the crowd.
German second seed Angelique Kerber, who beat Serena Williams in the Australian Open final for her first Grand Slam title, plays American Madison Keys on Wednesday for a semi-final spot.
Australian 24th seed Nick Kyrgios, the youngest top-30 ATP player at age 20, reached the quarter-finals with a 7-6 (7/3), 6-3 victory over Russia's 51st-ranked Andrey Kuznetsov.
The Aussie never trailed in the tie-breaker and took the only break of the second set when Kuznetsov double faulted away the fourth game.
Kyrgios, off to a career-best 13-3 start that includes his first ATP title last month at Marseille, next plays Canadian 12th seed Milos Raonic, who ripped Bosnian Damir Dzumhur 6-0, 6-3.
Raonic breezed through the first set in 21 minutes and ended matters with his 11th ace after only 54 minutes.
Raonic owns a 2-1 rivalry edge but this will be their first match outside the Grand Slams. He won in 2014 at the French Open and Wimbledon but lost to Kyrgios last year at Wimbledon.
Belgian 15th seed David Goffin beat Argentina's 112th-ranked Horacio Zeballos 7-5, 6-3 and next faces French 18th seed Gilles Simon, who routed compatriot Lucas Pouille 6-0, 6-1.
Scores on Tuesday from the eighth day of the ATP and WTA Miami Open (x denotes seeded player):
David Goffin (BEL x15) bt Horacio Zeballos (ARG) 7-5, 6-3
Tomas Berdych (CZE x7) bt Richard Gasquet (FRA x10) 6-4, 3-6, 7-5
Gilles Simon (FRA x18) bt Lucas Pouille (FRA) 6-0, 6-1
Nick Kyrgios (AUS x24) bt Andrey Kuznetsov (RUS) 7-6 (7/3), 6-3
Milos Raonic (CAN x12) bt Damir Dzumhur (BIH) 6-0, 6-3
Novak Djokovic (SRB x1) bt Dominic Thiem (AUT x14) 6-3, 6-4
Gael Monfils (FRA x16) bt Grigor Dimitrov (BUL x26) 6-7 (5/7), 6-3, 6-3
Kei Nishikori (JPN x6) bt Roberto Bautista Agut (ESP x17) 6-2, 6-4
Timea Bacsinszky (SUI x19) bt Simona Halep (ROM x5) 4-6, 6-3, 6-2