The Lions sit narrowly above the relegation zone but only goal difference separates them from Blyth Spartans in 21st place, with basement-side AFC Telford United only two points further back.
Brackley made a good start on Saturday when a strong run by Ellis Myles found Lee Ndlovu who hit a shot first time onto the crossbar.
Myles made another surging break and this time after a one-two with Tre Mitford, he put in a cross to Matt Lowe who was unmarked in the area and scored with a tap-in.
In added time the hosts so nearly gained a deserved second, Mitford hitting the bar with a powerful effort that looked set to go in.
A powerful drive from distance by Prince Ekpolo then forced Danny Lewis into a smart save in what was Guiseley’s first real chance of the game.
Lowe could have doubled his tally and the lead for the hosts after producing a strong run and shot. New loan goalkeeper Owen Mason, made a good stop to keep the score at 1-0.
There would be yet another opportunity for the home side when Mitford looked to have picked his spot, but a combination of bodies in front of the line, were able to block and it was eventually cleared.
The effort was certainly there for the Lions, yet chances really were at a premium with a late throw-in directed into a crowded area, but the ball was cleared and Guiseley slipped to their 10th league defeat of the season.
After the game, Lions joint-boss Marcus Bignot said: “Off the back of the performance and result against Southport, confidence can be low. We just ran out of time in the second half.”
A run of five home games without conceding a goal ended in comprehensive style as Farsley Celtic were beaten 4-3 by Gateshead.
Paul Blackett opened the scoring before the Celts hit back with two goals in as many minutes. First, Will Hayhurst converted a penalty, won by Adam Clayton.
Then, Chris Atkinson headed in Luke Parkin’s free-kick.
Jordan Richards made it 3-1 after heading in Hayhurst’s cross but ex-York striker Macaulay Langstaff replied with his 15th goal of the season before Jimmy Spencer was red carded for the hosts after a 62nd-minute aerial clash.
Gateshead went on to equalise through Cedwyn Scott before Adam Campbell grabbed the stoppage-time winner.
Bradford Park Avenue goalkeeper George Sykes-Kenworthy earned his team a 1-1 draw at Leamington following a late penalty save from Dan Turner.
Brad Dockerty’s opening goal for Avenue had earlier been cancelled out on 70 minutes by Kelsey Mooney.
Elsewhere, 10-man York City held on for a 1-1 draw against high-fliers Chorley in front of a record crowd of 4,512 fans at the LNER Community Stadium.
City’s Akil Wright opened the scoring before centre-back Matty Brown was sent off in the 33rd minute.
Harry Cardwell then secured a share of the spoils for the visitors before the half-time break.