PARIS, France (AP) — Less than 48 hours after learning of the death of his childhood coach, Novak Djokovic was on court at the French Open, determined to complete a career Grand Slam in honour of the woman he likened to a “second mother”.

Still grieving, Djokovic began shakily yesterday. Six of the match’s first seven unforced errors were his. After one poor exchange, he chucked his racket hard enough to break it. He dropped a set for the only time in four matches so far.

After recovering quickly to dispatch 16th-seeded Philipp Kohlschreiber of Germany 4-6, 6-3, 6-4, 6-4 and reach the quarter-finals at a 16th consecutive major tournament, Djokovic spoke from the heart about the passing of Jelena Gencic, who was 76.

“It hasn’t been easy, but this is life. You know, life gives you things (but also) takes away close people,” Djokovic said. “We were very close throughout my whole life, and she taught me a lot of things that are part of me, part of my character.”

Gencic connected with a six-year-old Novak at a tennis camp, then worked with him for five years.

Djokovic need to beat three more opponents to accomplish that, starting with 12th-seeded Tommy Haas, who at 35 became the oldest French Open quarter-finalist since 1971 by eliminating Mikhail Youzhny 6-1, 6-1, 6-3 in less than one-and-half hours.

By the second set, Youzhny was so out of sorts he destroyed a racket by slamming it nine times against his sideline seat.

Haas is a four-time Grand Slam semi-finalist who climbed to number two in the rankings at age 24. But recent times have been difficult because of a series of serious injuries and operations, including to his right shoulder and hip, and he missed more than a full season.

He’s certainly persistent.

The 12 French Open appearances it took Haas to reach his first quarter-final in Paris is a record. And he needed 13 match points in the third round to get past John Isner in five sets.

If Djokovic can get past Haas, he’ll find a familiar foe in the semi-finals: Seven-time French Open champion Rafael Nadal, who played his first relatively routine opening set of the tournament and put together a 6-4, 6-1, 6-3 victory over number 13 Kei Nishikori of Japan.

Nadal, who beat Djokovic in last year’s final and is 56-1 in his French Open career, declared: “I played much better today than the first three matches. No doubt about that.”

Consider that something of a warning for number nine Stanislas Wawrinka, who was trailing by two sets when he got into an extended and animated argument with the chair umpire, demanding that a line judge be replaced. Wawrinka slowly, steadily turned the match around and won 6-7 (5), 4-6, 6-4, 7-5, 8-6.

Meanwhile, Maria Sharapova moved into the quarter-finals by beating 17th-seeded Sloane Stephens of the United States 6-4, 6-3, part of a rough day for Americans. The other two in action also exited in straight sets: 54th-ranked Jamie Hampton lost to 18th-seeded Jelena Jankovic 6-0, 6-2, and 67th-ranked Bethanie Mattek-Sands was beaten by 12th-seeded Maria Kirilenko 7-5, 6-4. Kirilenko, who’s engaged to two-time NHL MVP Alex Ovechkin of the Washington Capitals, now meets two-time Australian Open champion Victoria Azarenka, a 6-3, 6-0 winner over 2010 French Open titlist Francesca Schiavone.

Fifteen-time major champion Serena Williams, the only US singles player left, plays her quarter-final against 2009 French Open champion Svetlana Kuznetsova on today, when number four Agnieszka Radwanska faces number five Sara Errani.

The men’s quarter-finals today are 17-time major champion Roger Federer against number six Jo-Wilfried Tsonga, and number four David Ferrer against number 32 Tommy Robredo, the first man in 86 years to win three consecutive Grand Slam matches after dropping the opening two sets.