RIO DE JANEIRO, Brazil – No.2 seed Angelique Kerber overcame a slow start and overturned a 1-4 deficit in the first set to see off Eugenie Bouchard and make her way to the third round of the Olympic tennis event in Rio, 6-4, 6-2.

Bouchard was off to a flying start against Kerber, looking to extend her streak against Germany’s No.1 to four wins in a row. After fighting off a pair of break points in both of her service games, the Canadian got the first break of the match and consolidated for a 4-1 lead.

After the initial wobble, Kerber found her rhythm and famous consistency from the baseline to rattle off seven games in a row, erase Bouchard’s lead and grab the opening set and a break in the second. Bouchard saved a trio of match points to hold serve in a lengthy game for 5-2, employing line-to-line defense against the German to hit a forehand winner. But Kerber took the match at her next chance and made her way into the third round after an hour and 22 minutes.

Though both players stayed aggressive throughout, Kerber kept her margins cleaner than Bouchard, striking 24 winners and 19 unforced errors to the Canadian’s 22 and 36. She brought up 12 break points and converted four times, while Bouchard broke just once in five chances.

Kerber will go on to play Australia’s Samantha Stosur for a spot in the quarterfinals. The No.13 seed defeated Japan’s Misaki Doi 6-3, 6-4 to move into the third round.

Earlier in the day Madison Keys, one of two Americans left in the singles draw, came away the winner in a three-hour marathon against France’s Kristina Mladenovic 7-5, 6-7(4), 7-6(5), in the longest match of the Olympic tennis event so far.

“I’m obviously really happy with how I was able to compete today,” Keys said in the mixed zone after the win.

There were 11 breaks of serve during the first two sets alone as the momentum shifted back and forth. Keys was three points away from taking the match when she held a 4-1 lead in the second set tiebreak, but Mladenovic rattled off six points on the trot to send the match to a third set. Keys overcame a 3-5 deficit in the final tiebreak to edge past the Frenchwoman.

The American hit 49 total winners during the match to 64 unforced errors against Mladenovic’s 28 winners and 46 unforced errors. Keys’ big serve bailed her out of trouble in the third set, blasting six of her nine aces during the final set.

The American took a medical timeout during the match but later brushed off any lasting injury concerns.

“I felt like one of my ribs maybe moved, which wasn’t very comfortable but I’m feeling a little bit better now, I’m going to go see the trainers after,” Keys explained.

She’s set to play against Spain’s Carla Suárez Navarro next in the next round.