'S-HERTOGENBOSCH, Netherlands - No.7 seed Aleksandra Krunic battled into her second career final at the Libéma Open on Saturday, coming from a set and a break down to upset top seed CoCo Vandeweghe, 2-6, 7-6(4), 7-6(1).

The World No.55 trailed 6-2, 4-2 against the two-time champion and World No.16 before pulling off a stunner - saving two break points at 4-4 in the second set which would've seen the American and her big serve try to book a spot in the final, and later saving a match point in the final set.

"I'm a little surprised, proud of myself and verry happy. She's an awesome player and very powerful, and it's challenging for me to play against those players," Krunic said after the match.

"I was very happy that I was able to fight because I was a set and a break down and it's never easy - especially against CoCo."

The Serb reached the final at the Guangzhou Open last fall before falling to home favorite Zhang Shuai, but looked far away from repeating that result as she was quickly put on the back foot by the American's power tennis. 

The opening stages of the match were edgy and tightly contested from both players, with each of the first five games seeing break point opportunities carved out.

However, the 25-year-old Serb's forehand proved insufficiently reliable as she leaked 13 unforced errors - and on serve, two double faults put her at an immediate disadvantage by a break down in the very first game.

Coming into the semifinals, Vandeweghe led the field in terms of first serve points won, and the American's booming delivery was key to maintaining her early lead.

Vandeweghe saved all three break points she faced in the opening set, and dropped just two points behind her delivery in three games to begin the second set.

However, Krunic continued to plug away on return, and her first break point opportunity of the second set came thanks to a delicate lob over the 6-foot-1 Vandeweghe, which she duly converted to get the match back on serve.

A tiebreak would ensue, and this time it was Krunic's turn to move through the gears - with three supreme backhand winners down the line sending the match to a deciding set.

"I tried to move her as much as I could, though sometimes it's challenging because of the powerful shots that she has," Krunic assessed. "I think I was returning well at the key points, and I just tried everything that I could."

The final set saw Krunic take an early lead for the first time in the match with a break in the third game, only to see Vandeweghe hit back and level proceedings in the sixth.

There was little to separate the two players for nearly the duration of the set until Krunic saved a match point as Vandeweghe misfired off the ground in the 10th game. That proved to be the key moment for the Serb to power through to her second career final, as she motored past an erratic Vandeweghe in the decisive tiebreak and sealed victory in two hours and 35 minutes.

"It's my second final, so it definitely feels amazing. It's not like I'm playing them every week, so I'm very happy that I'm improving and I'm being consistent," Krunic said.

"There are a lot of positives I can take from this match and I'm looking forward to tomorrow."