Nathaniel Chalobah fired the visitors into an 11th minute lead with a well-taken volley from the edge of the area but Austin equalised 17 minutes later from the penalty spot.
Burnley boss Sean Dyche made three changes, with David Edgar and Kevin Long replacing suspended duo Chris McCann and Michael Duff, while Danny Ings was handed a first start of the season in place of Brian Stock, who dropped to the bench.
Watford welcomed back Almen Abdi to the side for his first start since November due to injury, while Alexandre Geijo replaced Matej Vydra in attack.
The visitors went ahead after just 11 minutes through on-loan midfielder Chalobah. Burnley failed to deal with a succession of Watford corners and, after the ball was partially cleared, Chalobah volleyed in from edge of the area for his second Hornets goal.
And the Clarets were soon level. Referee Phil Gibbs had no hesitation in awarding a spot-kick after Joel Ekstrand pushed Dean Marney in the area and Austin calmly sent Manuel Almunia the wrong way.
Dyche's side were on top and Kieran Trippier's shot from the edge of the area tested Almunia, who could only gather at the second attempt. Then Danny Lafferty's deep cross was headed goalwards by Austin but the Spaniard saved well.
Just before half-time, Martin Paterson broke down the flank and Austin was denied a tap-in by a crucial intervention from Tommie Hoban.
Mark Yeates replaced Chalobah at half-time for the visitors to make his 300th career appearance, and the Hornets started the second half brightly with Troy Deeney going close.
The striker, who was aiming to equal the club record for scoring in seven successive games, was denied twice by Lee Grant as the Burnley keeper saved the Deeney's far-post header with his legs and recovered quickly to block the follow up.
But Burnley soon found their rhythm again and almost went ahead as Trippier's dangerous cross was met by Austin, but his diving header was held well by Almunia.
There were loud shouts from the home fans for a penalty with 16 minutes left as the ball struck Marco Cassetti's arm in the penalty area, but the referee decided it was not deliberate.
Watford were still a threat on the counter and Ekstrand came within inches of a spectacular goal but his long range effort crashed off the bar. But neither side was able to force a late winner as the game ended all-square.