Delhi posted 224-4 courtesy of a 113-run stand between Pant (88) and fellow left-hander Axar Patel, who hit 66
The victory came hours after third-seeded Milos Raonic of Canada, suffering from a hamstring injury, withdrew before his third-round match.
Nishikori, the runner-up to Novak Djokovic last year, fired 37 winners but Verdasco, aided by persistent swirling winds, used his varying pace and depth to rattle the eventual winner, inducing 48 unforced errors.
Verdasco rallied to force a first-set tie-break after trailing 3-0 but Nishikori's lunging half-volley backhand winner enabled him to take the set.
Nishikori served for the match at 5-4 in the second set but Verdasco saved a match point to break back and eventually forced a decider with a scorching cross-court backhand.
Nishikori won six of seven games in the third set to advance to the Round of 16.
Raonic had been scheduled to play American qualifier Jared Donaldson in a third-round match.
"It's related to the previous injury I sustained almost four weeks ago... in Delray Beach," he told reporters.
"It's the same muscle in the hamstring, up high. It got progressively worse after my first round. It seemed like it was not possible for me to compete today without putting myself at significant risk."
Raonic said he would not return until he felt 100 percent fit again.
"That could be in two weeks; that could be a little bit longer."
Delhi posted 224-4 courtesy of a 113-run stand between Pant (88) and fellow left-hander Axar Patel, who hit 66
The move is seen as part of Ukraine's efforts to reinforce its army as soldiers struggle to hold positions against Russia
The Jamaican currently holds world records in the 100m, 200m and 4x100m with times of 9.58s, 19.19s and 36.84s respectively
Total property income posted year-on-year growth of 10% to $74m, highest value ever
All official donation channels however remain open through the outlets announced by government agencies
The Starlight Park is a four-building freehold community in Meydan
The 22-time major champion admits his farewell tour hasn't been as enjoyable as he would have hoped
Eating out, poor hand hygiene and erratic weather may be among causes, say medics