The reigning Australian Open champion Roger Federer had a lot to play for in the second round at the Gerry Weber Open in Halle. The former world number one wasn't just playing for a berth to reach the quarterfinals in Halle, he was playing for a crucial top four seeding spot at Wimbledon.

Federer's compatriot Stan Wawrinka who reached the French Open final losing to Rafael Nadal participated at the Aegon Championships at the Queen's Club. Wawrinka lost to Feliciano Lopez in the first round, which meant that Federer needed to reach the quarterfinals in Halle to secure a vital top four seeding at Wimbledon, where he will not face Andy Murray or Novak Djokovic until the semifinals at least. The 35-year-old dispatched Mischa Zverev, 7-6 (4), 6-4 advancing to the quarterfinals in Halle for the 15th time, where he will play the defending champion, Florian Mayer.

Federer is made to work hard to claim the first set

In their solitary grass court meeting four years ago in Halle, Federer thrashed Zverev, 6-0, 6-0 in a mere 45 minutes. Moreover, Federer held serve easily to lead 1-0, and Zverev managed to do better than their last meeting in 2013 on grass as he held to love to restore parity at 1-1.

Both players continued to hold onto their service games rather comfortably, and Zverev, who is at a career-high ranking of 29 will be seeded at Wimbledon for the first time in his career, continued to employ his serve and volley tactic emphatically. However, at 3-3, Federer was in a spot of bother on his serve.

The 18-time Grand Slam champion trailed at 15-30 on his service game, and he got to game point with some good serving. Furthermore, he was taken to deuce twice, and he finished off the game with a smash at the net to take a 4-3 lead. The elder of the Zverev brothers remained untroubled on his serve as his serve and volley tactic continued to work effectively.

Moreover, the eight-time champion started to employ the serve and volley tactic as well, and he held to love taking a 5-4 lead in the business end of the first set. The 29-year-old from Germany was under pressure on his serve for the first time in the match. Zverev was serving to stay in the opening set and he committed a double fault to hand Federer a first set point at 30-40.

The 29-year-old is enjoying a career best year and he will be a threat going forward at Wimbledon (Photo by Carmen Jaspersen / Getty)
The 29-year-old is enjoying a career best year and he will be a threat going forward at Wimbledon (Photo by Carmen Jaspersen / Getty)

It was a gutsy save from Zverev as he sent down a big second serve to save it but a second one quickly followed for Federer, who produced a stunning forehand winner down the line with the German at the net.

Once again, the unseeded German fended it off with style by producing a scintillating volley winner at the net with Federer trying to find a backhand winner down the line. Both players continued to produce good tennis and went back and forth to deuce and Federer created a third set point with a good return forcing the error from Zverev.

The 29-year-old saved it with a good serve out wide and he eventually held onto his serve in a lethargic 11-minute game with a good first serve out wide.

The destination of the first set was inevitably heading to a tiebreak. The former world number one raced out to a 3-1 lead but Zverev claimed the next three points to lead 4-3 as Federer missed a crucial smash which would have given him an unassailable 4-1 lead. Nevertheless, the German was buoyed by that miss as he sent down an ace out wide with that lead.

The Swiss maestro regrouped as he won the next two points on his serve, and he was able to put away an overhead smash winner to lead 5-4. The world number five created his fourth set point with a backhand return winner down the line, and he claimed the opening set with a backhand winner down the line to claim it 7-6 (4) in 53 minutes.

Federer breakthroughs to reach the quarterfinals for the 15th time

Both players held onto their serves in the opening two games of the second set. It was vital for Zverev to hold onto his serve as the 18-time Grand Slam champion would have run away with the match.

The world number 29 found himself at 0-30 on his serve but he reeled off the next four points, sealing it with an ace down to T, nudging the scoreboard in his favor. The Swiss maestro remained untroubled on his serve as he held to love, leveling the second set at 2-2.

The former world number one's quest for an eighth title continues against Mayer on Friday (Photo by Carmen Jaspersen / Getty)
The former world number one's quest for an eighth title continues against Mayer on Friday (Photo by Carmen Jaspersen / Getty)

Both players continued to trade from behind the baseline, and Zverev would come forward to finish off points quickly. The second set was flowing at a nice pace and it seemed likely that a second set tiebreak was going to decide the second set.

However, at 4-4, Zverev played one of his worst service games of the match as he quickly found himself at 15-40, staring defeat in the face as Federer created two break point chances. The former world number one brought up the break points with a ridiculous forehand on the run, forcing Zverev to cause an error at the net. The eight-time champion converted the break point, breaking Zverev's serve for the first time in the match with a forehand winner down the line.

The world number five had no problems serving for the match as he brought up his first match point with an ace down the T, and at the second time of asking, the former world number one sealed his place in the quarterfinals producing a sweet half-volley winner, setting up a quarterfinal encounter with another German in the defending champion Florian Mayer.