Novice New Zealander quick William O'Rourke rattled Sri Lanka with a five-wicket haul with the hosts ending their first innings on 305 on the second morning of the first Test on Thursday.

Sri Lanka belatedly resumed from 302-7 overnight in Galle after a rain delay but conceded all three remaining wickets for just three runs.

O'Rourke (5-55) managed consistent speeds above 145 kilometres (90 miles) per hour to carve through the Sri Lankan top order on day one before sending back the final two batsmen, Ramesh Mendis and Asitha Fernando.

It was his second five-wicket haul in just three matches after his 9-93 against South Africa at home in February, the best match figure for a debutant Kiwi bowler.

A groin injury had ruled O'Rourke out of the following series against Australia and his selection ahead of the more experienced Matt Henry had been a surprise.

A back to the wall century by Kamindu Mendis (114), his fourth from seven Test appearances, rescued Sri Lanka from a worrisome 178-5 on day one.

Rain delayed play for nearly an hour in the morning and a fresh downpour halted the match again soon after the innings change, with openers Tom Latham (1) and Devon Conway (4) at the crease.