Lovenkrands broke the deadlock with a crisp finish from the edge of the area, but DJ Campbell's 32nd-minute strike meant the Magpies were only level at the break.
Blackpool were the better side for the majority of the game, but Newcastle rode their luck to claim a result that edges them another point closer to being mathematically certain of survival.
Alan Pardew made one change to the side that drew with Manchester United on Tuesday, with Kevin Nolan replacing Danny Guthrie after completing his two-match suspension.
The game had a competitive edge from the start, with Keith Southern dumping Joey Barton into the advertising hoardings early on, and Newcastle claimed the lead with their first meaningful attack in the 17th minute.
Joey Barton capitalised on a mistake by Charlie Adam to win possession, the midfielder shuffled the ball inside to Lovenkrands, and the Dane drilled a fine low finish into the bottom right-hand corner of the net.
Blackpool had offered little at that stage, but the hosts finished the first half strongly and could have claimed more than one goal for their efforts.
As it was, their equaliser came on the half-hour mark, with Campbell producing a backheel flick to propel an Adam corner into the net. Jose Enrique did his best to produce a goalline clearance, but the ball had clearly crossed the line before the Spaniard headed it clear.
Campbell and Matt Phillips had both gone close by that stage, and Blackpool were unfortunate not to be awarded at least one penalty before the break.
First Krul appeared to take both Campbell and the ball as he prevented the striker from rounding him, then Danny Simpson appeared to touch the ball with his arm as he tumbled in his own area.
There was also one more scare for the visitors before the interval, with Enrique blocking Alex Baptiste's shot on the line as another of Adam's corners caused problems in the 18-yard box.
The interval came at a good time for the Magpies, and having regrouped, they improved in the early stages of the second half.
Shola Ameobi drilled over from the edge of the area while, at the other end, Adam curled a low free-kick just past the left-hand post.
Pardew introduced Stephen Ireland shortly after the hour mark in an attempt to provide Newcastle with some momentum, but his side were almost behind when Gary Taylor-Fletcher headed Stephen Crainey's cross narrowly over the crossbar shortly after.
Blackpool went even closer in the 66th minute, with Adam's low drive from the left corner of the box rebounding off the base of the post with Krul beaten.
BLACKPOOL (4-3-3): Gilks; Eardley, Baptiste, Evatt, Crainey; Southern, Vaughan, Adam; Phillips (Varney 83), Taylor-Fletcher (Puncheon 89), Campbell.
Subs (not used): Kingson (gk), Cathcart, Reid, Ormerod, Beattie.
NEWCASTLE (4-4-2): Krul; Simpson, Williamson, Coloccini, Enrique; Barton, Tiote, Nolan (Perch 86), Gutierrez; Lovenkrands (Ireland 62), Ameobi (Kuqi 90).
Subs (not used): Soderberg (gk), S Taylor, R Taylor, Ranger.