Gareth Southgate was able to celebrate his 50th match as manager of his country with a Group I victory which should have been much more emphatic on Friday (AEDT).

James Ward-Prowse opened the scoring with his first senior international goal before Calvert-Lewin and Raheem Sterling got in on the act in a first half that saw England waste a host of clear-cut chances.

Calvert-Lewin doubled his tally early in the second half and substitute Watkins was on target on his Three Lions bow on another tough night for a San Marino team sitting at the bottom of the FIFA rankings, with much bigger tests to come for England on the road to Qatar 2022.

San Marino was chasing shadows from the start, but Calvert-Lewin somehow failed to convert Reece James' cross and Sterling – named as captain with Harry Kane on the bench – was off target with two close-range headers.

It was only a matter of time before England took the lead and Ward-Prowse was the man to put them in front, sweeping home Ben Chilwell's cutback with his left foot 14 minutes in.

Calvert-Lewin doubled their advantage by nodding in James' inviting cross and Chilwell's rasping drive was superbly tipped over by Elia Benedettini before Sterling punished San Marino for trying to play out from the back, cutting inside before finding the net with a deflected right-foot finish.

England was relentless, with Mason Mount pulling the strings, and the recalled Jesse Lingard scuffed wastefully wide from close range before he was denied by a brilliant save from Benedettini late in the first half.

Southgate made four changes at the break, with Jude Bellingham and Phil Foden among the quartet to come on and Sterling handing the armband to Conor Coady.

It was all too easy for England as Calvert-Lewin tapped in the lively Lingard's cross in the 53rd minute, but there was to be no hat-trick for the Everton striker as he was replaced by Watkins.

Ward-Prowse came close to a second when Benedettini produced another fine save to keep out the midfielder's whipped free-kick and Watkins volleyed into the turf and over the crossbar moments later.

Watkins was not to be denied seven minutes from time, though, controlling the ball just inside the area and drilling home with his right foot.