Vesnina beat Yanina Wickmayer of Belgium 6-2, 6-0 in 51 minutes and will be bidding for her second title of the year after winning Hobart in January.
The pair will meet not only in the Eastbourne final but also in the first round at Wimbledon. If he could win only one of the matches, Lopez would prefer to win at this tournament.
"It's funny, funny to play the same guy in three days," Lopez said. "But this is tennis, and sometimes these things can happen, no? Final is a final. To win the tournament is not easy, so for the moment I take this one, obviously."
Hampton took 2 hours, 44 minutes to secure her victory in a match that included 35 break points and 14 breaks of serve.
The American had several chances to win the opening set, holding three set points at 5-4, serving for the set at 5-4 and 6-5 and then holding two further set points in the tiebreaker.
In the second set, Wozniacki struck a dazzling crosscourt backhand winner to break for 5-4 before rain caused a brief delay.
When play resumed, Wozniacki failed to serve out the match and Hampton first held off two break points to hold for 6-5 and then broke for 7-5 on her third set point.
After an early exchange of breaks in the final set, Wozniacki netted a backhand to give Hampton a decisive break for 5-3.
"I stuck with it," Hampton said. "I think that I stayed positive even though I had a few set points in the first and kind of choked them away a little bit and got down a break in the second and think I was down love-40 on my serve (at 2-4).
"Just to get the hold there and stick with it and stay positive was definitely a plus. I'm definitely proud of myself."
Hampton is disappointed that she has drawn fellow American Sloane Stephens in the first round at Wimbledon.
"It's a bit of a bummer that two Americans have to play first round, but I'm going to treat it just like every other match," Hampton said. "But we're not there. I have a match tomorrow to worry about yet."
Wozniacki considered that the match had been of a high standard in conditions made difficult by the wind.
"I had my chances, I didn't take them and she played very well, I have to say," Wozniacki said.
After a difficult time during the clay-court season when she won just one of her last six matches, Wozniacki is satisfied with her game now as she heads into Wimbledon.
"Overall I'm feeling good, I feel happy to be on grass," she added. I feel like my game is where I want it to be."