Serena Williams advances to Quarter Final of The Cincinnati 2015.

In the pair's first career meeting, Williams came out on absolute fire, ripping through the first nine games of the match for a 6-0, 3-0 lead. Knapp held her serve in the 10th game to get on the board and the two traded holds the next few games until the No.1-seeded Williams pounced one last time, breaking the Italian for a 6-0, 6-2 victory, finishing the match off with one last forehand up the line. Williams finished the 54-minute match with nearly twice as many winners as unforced errors (15 to 8). 

 "More than anything I was just trying to stay positive and trying to have fun," Williams said in her on-court interview. "I did so well here last year, so I just really want to stay in the tournament." Williams is the first player to reach 45 matc
h wins on the year - she's 45-2 overall now. She's also won 41 matches in a row on US hardcourts. The last loss she's had on hard on home soil came in the final in Cincinnati two years ago, losing to Victoria Azarenka in a third set tie-break.