Elina Svitolina's mastery of Daria Kasatkina continued Wednesday at the Mubadala Citi DC Open.

The unseeded Ukrainian moved through to the third round at the WTA 500 event with a 6-2, 6-2 win over Kastakina, the No. 5 seed and World No. 11, extending her head-to-head record against her to 8-0 in the process.

In those eight matches, Svitolina has only lost two sets. 

Svitolina is now 2-0 against Kasatkina this year, having also won in straight sets in the fourth round of Roland Garros, and is through to her fourth quarterfinal in her last five events played. This week's event in Washington, D.C. is just the eighth tour-level event of Svitolina's comeback from her maternity leave, which began in Charleston in April.

"I just try to fight each time I play Dasha. She's a tough opponent to face, and each time, I try to play just one extra ball over the net, to take and dictate the game. I'm really happy I won the match today."

Svitolina hit 29 winners off the ground, 22 on her forehand, and saved all 10 break points she faced against Kasatkina in 1 hour and 36 minutes in hot and humid conditions.

Nine of those break points came in a pair of games: six in a five-deuce game to win the first set, and three more an 11-deuce marathon at 4-1 in the second set. From 2-1 down in the opener, Svitolina won nine straight games to establish a 6-2, 4-0 lead. 

Svitolina will next face either of a pair of Americans: No.1 seed and 2019 D.C. champion Jessica Pegula, or lucky loser Peyton Stearns.

Elsewhere on Tuesday afternoon, No.6 seed Belinda Bencic also moved through to the third round with a straight-sets win, beating 2016 D.C. finalist Lauren Davis 6-1, 6-4.