BNP Paribas Open: Roger Federer clinches hard-fought 7-6, 7-6 victory over Steve Johnson, set up 4th round clash with Nadal

Swiss tennis ace Roger Federer overcame a stiff challenge against American Steve Johnson to clinch a hard-fought 7-6 (3), 7-6 (4) win at the BNP Paribas Open, setting up a fourth-round match against Rafael Nadal.

Federer fired 12 aces - his fastest serve registering 131 mph - and never faced a break point against Johnson, who reached 136 on the radar gun and fought off all four break points against him.

Nadal advanced with a 6-3, 7-5 win against 26th-seeded Fernando Verdasco for his 50th career victory at the desert tournament, where he's won three titles but none since 2013.

Five-time Indian Wells winner Novak Djokovic defeated 2013 finalist Juan Martin del Potro 7-5, 4-6, 6-1 and next faces Nick Kyrgios in the same quarter of the draw as Federer and Nadal.

On the women's side, No. 2 seed Angelique Kerber lost to 14th-seeded Elena Vesnina 6-3, 6-3 in the fourth round. Kerber is assured of retaking the No. 1 ranking from injured Serena Williams next week.     

Federer is a four-time champion at Indian Wells who won his last title in 2012. He defeated Nadal in the Australian Open final in January for his record 18th Grand Slam title.

Their meeting on Wednesday will be the earliest they have played since their first match in 2004 at Miami, where Nadal won.

"Because it's early in the tournament, I think we both don't quite yet know to 100 percent how everything feels," Federer said. "There is a bit of the unknown, which is exciting maybe for the fans to see how we're going to try to figure that part out."

Federer hit 32 winners against Johnson, including a forehand volley that earned him a mini-break in the first set tiebreaker. He won five of the next six points and closed out the set on Johnson's desperate backhand lob that landed wide.

Johnson held at 6-all to force the second tiebreaker and fell behind 4-2. He broke Federer for a 4-all tie before Federer won on his second match point when Johnson netted a backhand.

"In the second set, I think he was serving almost 90 percent at one point," Federer said. "That's why I changed my position on the return. I was trying to mix it up a bit."

Nadal closed out his 1 1/2-hour, third-round match in 95-degree (35 C) heat with a forehand winner.