Both players struggled to find their best form in a tense contest but it was the Londoner who showed the greater mental strength to peg back Walden who won the first two frames of the day.
The second frame loss was a particularly cruel blow for Hawkins as he fell behind 11-7 after a bad bounce off the cushion left him out of position on a black.
That led to a clear-up of 63 by Walden to take the frame by a single point.
Hawkins dusted himself down though to sink a long red and it was the start of his first century of the semi-final, a break of 114.
Walden hit back to retain his four-frame lead going into the interval after he took advantage of Hawkins going in-off with the cue ball.
The battling qualities that Hawkins has been working on with former world champion Terry Griffiths came to the fore after the players returned.
He chalked up his second century of the match with a break of 104 before he knuckled down to take the next frame, a marathon one which lasted up to a hour.
Both players had opportunities to take the frame but Hawkins held his nerve to come within two frames of his opponent.
Chester's Walden began to feel the heat as he struggled to find any fluency to his game as Hawkins grinded out the next frame.
A break of 66 from Hawkins secured the last frame and brought him level for Walden for the first time since they cued off the semi-final on Thursday.
Walden will now have to find his mental fortitude after he saw a four-frame lead wiped out to set up an intriguing deciding final session tonight.