ADELAIDE, Australia (AFP) — Novak Djokovic overcame a shaky start to beat Frenchman Quentin Halys and reach the Adelaide quarterfinals, stepping up his preparations for the Australian Open.

The top seed from Serbia won 7-6 (7/3), 7-6 (7/5) and will face Canada's Denis Shapovalov in the last eight of the Adelaide International.

Djokovic returned to the scene of his 2007 title run on Tuesday with a comfortable straight-sets win over France's Constant Lestienne.

He backed that up against Lestienne's doubles partner Halys but was slow to get going, slumping 2-5 in the first set before clinching victory.

"It was a great performance from my opponent today," said the 35-year-old Djokovic, who is warming up for a tilt at a 10th Australian Open title after missing last year's Grand Slam when he was deported over his vaccination status.

"He played like a top-10 player today."

"As far as my game goes, I feel good on the court," Djokovic added.

"I didn't have such a great start and he was serving really well. Tough to break so two tiebreaks were probably the most realistic score."

With the crowd firmly behind the former world number one on a packed center court, Djokovic — who won Wimbledon among five titles last year — lost his opening service game against the 64th-ranked Frenchman.

He earned two break points in game three but was unable to convert, biding his time until the seventh game, when he broke to love then raced through the tiebreak.

Nothing separated them in the second set, which again went to a tiebreak, after Halys saved two match points at 5-4, with Djokovic finally prevailing when Halys netted a backhand.

Djokovic's reward is a clash with world number 18 Shapovalov, who sailed into the last eight with a 6-4, 6-3 win over Russian qualifier Roman Safiullin.

Djokovic has won all seven previous encounters with the Canadian.

Shapovalov is still riding the wave of leading Canada to the Davis Cup title and said he was determined to maintain his good form.

"Definitely trying to implement that on the individual side. Obviously, so far, it's been a great start. Hopefully, I can capitalize on a good start to the week and definitely excited for what's to come," he said.

Also in the Last 16, American Sebastian Korda beat Spain's Roberto Bautista Agut 6-4, 6-4. Adelaide defending champion Thanasi Kokkinakis meets Jannik Sinner later Thursday.

In the women's draw, Czech teen Linda Noskova defeated American Claire Liu 6-2, 6-2 to power into the last eight where she will play either Victoria Azarenka or Chinese qualifier Zheng Qinwen.

But former French Open winner Jelena Ostapenko crashed out to Romania's Irina-Camelia Begu 6-3, 6-0, who will face Russian world No. 9 and fourth seed Veronika Kudermetova next.

Tunisian world No. 2 Ons Jabeur, who reached two Grand Slam finals last year, faces Romania's Sorana Cirstea later.