Novak Djokovic marched into the quarter-finals of the Shanghai Masters on Thursday after overcoming John Isner in straight sets at Qizhong Forest Sports City Arena. 

The top seed had to work hard in the first set before moving through the gears in the second and securing a 7-5, 6-3 win over the American.

Later in the day, Roger Federer overcame a sloppy opening set to get past David Goffin. The Swiss former world No. 1 will face Alexander Zverev, who held off a late comeback attempt from Andrey Rublev and triumphed 6-0, 7-6 (4) in the last fixture of the third round.

There was also a victory for Dominic Thiem, who comfortably beat Nikoloz Basilashvili 6-3, 6-4, 

Shanghai Masters - Thursday Results

(1) Novak Djokovic bt. John Isner: 7-5, 6-3

(2) Roger Federer bt. (13) David Goffin: 7-6 (6), 6-4

(3) Daniil Medvedev bt. Vasek Pospisil: 7-6 (7), 7-5

(4) Dominic Thiem vs. (15) Nikoloz Basilashvili: 6-3, 6-4

(6) Stefanos Tsitsipas bt. Hubert Hurkacz: 7-5, 3-6, 7-6 (5)

(10) Fabio Fognini bt. (7) Karen Khachanov: 6-3, 7-5

(11) Matteo Berrettini bt. (8) Roberto Bautista Agut: 7-6 (5), 6-4

(5) Alexander Zverev bt. Andrey Rublev: 6-0, 7-6 (4)

Friday Fixtures

(3) Daniil Medvedev vs. (10) Fabio Fognini, 5:30 a.m. BST/12:30 a.m. ET

(1) Novak Djokovic vs. (6) Stefanos Tsitsipas, 7 a.m. BST/2 a.m. ET

(2) Roger Federer vs. (5) Alexander Zverev, 11:30 a.m. BST/6:30 a.m. ET

(4) Dominic Thiem vs. (11) Matteo Berrettini, 1 p.m. BST/8 a.m. ET

Schedule via FlashScore.com.

Thursday Recap

The big challenge for Djokovic on Thursday was always going to be getting breaks of serve against the 6'10" Isner. In the end, the top seed went about his task in different ways in each set.

Unsurprisingly, the first was dominated by the serving player, with neither man giving up much. The first time any game went to deuce was when Isner held to make it 4-4, although it was a sign that Djokovic was beginning to figure out his opponent's serve.

Eventually, after moving 6-5 in front, the defending champion pounced and extended his excellent recent run of winning sets:

Having struck late in the opener, Djokovic was on the front foot early in the second stanza, taking his second break point of the match to go 2-0 up. Metro's George Bellshaw was impressed with what he was seeing from the 16-time Grand Slam winner:

After consolidating further to go three games ahead, it was always going to be too much of an ask for Isner, who was unable to make any dent on the world No. 1's serve.

Like Djokovic, Federer was also made to dig deep at times in his match, as Goffin proved to be a resolute opponent.

Of the two players, it was Goffin who appeared the more likely to break early on. In the latter stages of the set, when Federer typically comes into his own, it was the Belgian who played the better tennis too.

Goffin was profligate with the chances he created. The 13th seed had the chance to serve for the set and had five set points throughout the opening stanza. After they had all slipped by, Federer then took the first available to him in the tiebreak.

Tennis journalist Simon Cambers commented on a poor opening to the match for the No. 2 seed:

After that, normal service resumed for Federer in the second set, when he was much stronger on serve and grabbed the one necessary break needed to take the match.

Tennis TV reflected on some impressive figures after the win:

His reward for a gritty third-round display is a quarter-final clash with Zverev in what has the potential to be the best fixture of the next round.

The German showcased some of his best and worst traits in a straight-set win over Rublev, which began with a bagel scoreline running in his favour and alarm bells ringing for his Russian rival.

However, the second set ended in a tiebreak despite Zverev leading 3-0 and 5-2 at times, losing four of the final six games before eking out a victory with back-to-back breaks, via Tennis TV:

He and Rublev are known to be good friends on the circuit, but less forgiving opponents would have punished Zverev after he appeared to let up slightly close to the finish line. 

Elsewhere, Thiem was a routine winner against Basilashvili and appears set to continue the impressive form he showed last week to win the China Open.

The man the Austrian beat in that final, Stefanos Tsitsipas, is also into the last eight in Shanghai. Tennis writer Bastien Fachan commented on what has likely been a satisfying couple of days for the Greek:

Joining the other winners in the last eight is Medvedev, who continued his strong recent play with a battling win over Pospisil.

There was little between the two players, but the third seed was able to play the better tennis at the crunch moments late in each set.