The Clarets produced an encouraging first-half performance in their Sky Bet Championship clash and created several opportunities, but could not find the breakthrough.

Celestini made three changes following the game against Lincoln, with Jamie Vardy, Marcus Edwards and Andreas Hountondji replacing Dastan Satpayev, Max Alleyne and Armando Broja.

There was also a major boost with captain Josh Cullen returning to the bench after more than 300 days out through injury, while Jaydon Banel was back in the squad following an injury suffered in pre-season.

Burnley made a bright start and Edwards quickly caused problems for the Portsmouth defence, weaving his way into the penalty area before seeing his effort kept out by Nicolas Schmid.

Edwards was involved again midway through the half, combining with Josh Laurent, whose cross was met by Hountondji, but the forward could only guide his header over.

The hosts continued to apply pressure and Kyle Walker was next to threaten, forcing Schmid to tip his effort over for a corner.

Hountondji then had another opportunity from inside the box, but his effort was comfortably gathered by the Portsmouth goalkeeper.

Burnley thought their dominance had finally been rewarded shortly before half-time when Largie Ramazani produced a fine strike from outside the area, only for the flag to go up for offside.

The Clarets therefore went into the interval goalless despite having controlled much of the opening 45 minutes.

Chances were harder to come by after the restart and Celestini turned to his bench, introducing Banel as his side searched for a breakthrough.

Ramazani nearly connected with a cross at the back post before Celestini made further changes.

Cullen received a warm welcome as he returned to action for the first time since last December, with Aaron Ramsey also introduced as Burnley pushed for a late winner.

Portsmouth, however, remained resolute and successfully frustrated the Clarets throughout the closing stages.

Burnley continued to push but could not find the decisive touch, leaving Celestini with a point from his first match at the helm and Portsmouth heading home with a hard-earned share of the spoils.