John Isner leans on 44-ace effort to advance in Melbourne

MELBOURNE -- For a while anyway, this match seemed destined for overtime.

After two extremely tight sets, No. 10 seed John Isner eventually pulled away, beating No. 18 Feliciano Lopez 6-7 (8), 7-6 (5), 6-2, 6-4 to reach the fourth round of the Australian Open.

Until the third set, Isner and Lopez had played five straight tiebreakers dating back to last season's Queen's Club encounter. In fact, 12 of their 21 career head-to-head sets to that point had been decided by tiebreakers.

Inspired by his clutch shot-making down the stretch of the second set, Isner broke Lopez three times in the last two frames.

Isner, who has won all 54 of his service games in Melbourne, did not face a break point Saturday. Fittingly, he finished the match with a 128 mph ace down the line, his 44th of the match, a tournament high and only seven shy of Joachim Johansson's Australian Open record.

To date, Isner has 101 aces in the tournament, 28 more than anyone else.

Now, for the first time in six years, Isner is into the fourth round at the Aussie Open.

"Yeah, it's a big win," Isner said. "It's a very tough opponent, especially for me, the way he plays. It certainly has given me trouble before in the past. Also been a little while since I've been in the round of 16 at this tournament. It feels great. I'm very relieved to get through, want to keep on going."

Isner, who had lost 10 of his last 11 Grand Slam matches versus seeded opponents, had opportunities to take the early lead but couldn't convert.

At 8-8 in a taut opening tiebreaker, Isner and Lopez engaged in a cat-and-mouse, 15-point rally, the longest of the match. It ended with Isner dumping a forehand into the net. On the next point, Isner ran around his backhand in favor of his stronger forehand, but the maneuver took him too far off the court. Lopez took advantage, sticking an easy slice crosscourt winner to secure the frame.

In the second-set tiebreaker, a terrific stab volley gave Isner the mini-break at 6-4. Two points later, a 135 mph missile out wide squared the match.

Isner then broke Lopez in the first game of the third set and rolled from there.

"Well, I wasn't happy after the first set, for sure," Isner said. "I was ticked off.

"My racket felt the brunt of that," he added with a smile.

"But I knew it was a lot of match to go. Again, obviously I was serving well. I was really just kind of tight and kind of wound up in that second set. The second set could have gone either way. That was definitely the turning point. I freed up and started playing so much better after that."

With the win, Isner has a potential schedule problem. He's from Greensboro, North Carolina, and his beloved Carolina Panthers host the Arizona Cardinals at 10:40 a.m. local time Monday -- the same day as Isner's fourth-round match.

"Maybe I'll go to the tournament desk and ask for a late start," Isner said. "I'm serious, actually. We'll see if I can get that done."

Isner, who will play David Ferrer, then said he needs to stay focused.

"Yeah, my last match in 2015, he beat me in Paris," Isner said of Ferrer. "I've got to play aggressive. I mean, he's going to want to get on top of that baseline and move me around all day. He's not going to get tired. We all know that.

"I've got to go for my shots and try to keep the points shorter. Can't be having long, drawn-out rallies with him. I'm definitely not going to win the majority of those."

No. 4 Stan Wawrinka also advanced, beating Lukas Rosol 6-2, 6-3, 7-6 (3).

It was a routine victory for Wawrinka, who with 18 aces notched his 400th career match win.

Coming off a title at the Chennai Open, Wawrinka improved to 7-0 this season and has won all 16 of his sets.

Wawrinka's breakthrough major came here in 2014, when he stunned Rafael Nadal in the final. That season, he became the first player in 21 years to defeat the Nos. 1 and 2 seeds en route to a Grand Slam title.

With a French Open title last year, Wawrinka has two won majors in the past two seasons -- more than Andy Murray, Roger Federer and Nadal combined.

After the win against Rosol, Wawrinka entertained the Rod Laver Arena crowd with a lighthearted on-court interview.

On his neon pink ensemble: "This one is quite flashy. At least everyone can see me in the stadium."

On his raspy voice: "I've been OK the past few days. Maybe just a few too many cigars. If I talk, perhaps I talk too much s---, so perhaps it's better I don't."

Wawrinka next plays Milos Raonic, against whom he is 4-0.

Coming off a title in Brisbane to start the season, Raonic overwhelmed Viktor Troicki in just 1 hour, 46 minutes. Raonic finished the match with 37 winners and broke his Serbian opponent five times.

Raonic has yet to lose a set, but he was broken in the first game of the third, ending a streak of 41 straight holds.

At 7-0 this season, Raonic, 25, is growing in confidence by the day.

He dedicated Saturday's win to victims of a shooting in Canada that left four people dead and at least two injured. A gunman opened fire at the La Loche Community School in a remote aboriginal community in Saskatchewan and at a second location.

"Today, before I stepped out on court, it was a difficult day back home," he said, his voice sounding emotional at times. "Unfortunately, in Saskatchewan, in a very small community, there was a shooting at a high school, so I want to take a moment and give thoughts to that community, the family, the students and the school affected. We wish you all the best."

Information from The Associated Press was used in this report.