Ulster suffered a surprise Guinness PRO14 defeat as they came unstuck 27-23 against Italian opponents Zebre at Stadio Sergio Lanfranchi.

Despite leading at the interval, Ulster conceded 21 second-half points and had to be content with a losing bonus point.

Zebre took an early lead through a Carlo Canna penalty, but Ulster responded with an Andrew Trimble try that John Cooney converted.

A second Canna strike narrowed the gap, but Ulster appeared to have a degree of breathing space by half-time as two Cooney penalties opened up a 13-6 advantage.

Zebre, though, began the second period in blistering fashion, with flanker Giovanni Licata claiming a try that Canna converted, then wing Mattia Bellini posted a touchdown converted by Marcello Violi.

Ulster had it all to do entering the final quarter, but although a Cooney penalty narrowed the gap, Zebre made the game safe when number eight Renato Giammarioli scored his team's third try, with Violi again adding the extras.

The visitors then had the final say through a Darren Cave try that he also converted, but it was a case of too little, too late.