SO much for there being no easy games in international football.

England barely broke sweat as they regained top spot in their World Cup qualifying pool by slamming five goals past the part-timers of San Marino, yet it was hard to detect any sense of drama or excitement on a night that exposed one of the major shortcomings of the international game.

Mismatches occur in football all the time, but few are as pronounced as this. The fact it will be repeated when England travel to Bologna next March merely adds to the sense of frustration.

Not that England's players will be complaining of course, and as a warm-up for the real business of the week – Tuesday's testing trip to Poland – last night's game just about served its purpose.

An early injury to Theo Walcott was an unwelcome blow, but goals from Wayne Rooney and Danny Welbeck in the space of three first-half minutes broke down some stubborn San Marino resistance and paved the way for a sustained second-half onslaught.

Three more goals arrived after the interval, one more apiece for Rooney and Welbeck, and a clinical strike from Alex Oxlade-Chamberlain that capped a promising display.

Ultimately, though, it was impossible not to question whether sides like San Marino should be playing in World Cup and European Championship qualifiers?

England's opponents kicked off as the joint-lowest side in FIFA's world rankings and are still to win a competitive fixture. Given that they failed to score a single goal in their ten qualifiers for Euro 2012, it is safe to assume they are unlikely to discover the winning habit any time soon.

Along with the likes of Andorra, Luxembourg and Liechtenstein they perennially find themselves at the bottom of their qualifying pool, yet seeded sides like England still have to go through the motions on nights like last night, when their opponents refused to even contemplate leaving their own half of the field.

It can be argued that San Marino's players will never improve if they are not given the opportunity to test themselves against the top-ranked sides, but there has been little discernible improvement in the last two decades, and if they are not even going to try to attack, the time has surely come to at least consider a round of pre-qualifiers.

San Marino's main contribution last night was the dreadful early challenge from goalkeeper Aldo Simoncini that has jeopardised Walcott's involvement in Warsaw in three days time.

The opening ten seconds passed without incident, an improvement on 1993 when Davide Gualtieri scored one of the most infamous goals in English footballing history, but things quickly took a turn for the worse.

Chasing Rooney's fourth-minute through ball into the area, Walcott was clattered by Simoncini, who just about took enough of the ball to avoid the concession of a penalty.

The collision was reminiscent of Harald Schumacher's assault on Patrick Battiston at the 1982 World Cup finals, and while Walcott eventually clambered to his feet, he was unable to continue.

In his absence, England laboured through the opening half-hour, lacking the guile, creativity or perhaps even brute strength to prise open a well-stocked San Marino defence.

The visitors regularly had all ten outfield players in their defensive third of the field, and it was weight of numbers rather than anything more technically proficient that frustrated England's attackers.

The floodgates remained locked for 35 minutes, although they were almost prised open by a long-range effort from Michael Carrick that crashed against the crossbar and a follow-up effort from Welbeck that rebounded off the post.

Oxlade-Chamberlain, who was lively throughout, also went close, and it was the Arsenal winger's through ball that helped create the opener.

Welbeck was upended by Simoncini as he galloped clear, and Rooney rammed home the penalty to claim his first goal for either club or country this season.

Wembley breathed a collective sigh of relief, and the crowd was on its feet again as England doubled their advantage two minutes later.

Aaron Lennon, the replacement for Walcott, crossed from the right, and after stealing ahead of his marker, Welbeck flicked the ball home with an improvised back-heel that was every bit as impressive as the one that fashioned a winner against Sweden in the European Championships. Early second-half chances came and went, most notably to Gary Cahill who failed to convert Tom Cleverley's floated cross and then headed Leighton Baines' corner over the crossbar, and it initially looked as though England might fail to add to their first-half efforts.

However, a spate of three goals between the 69th and 77th minutes gave the scoreline a more realistic look.

Rooney scored the first, moving ahead of Alan Shearer, Tom Finney and Nat Lofthouse to fifth on the all-time list of England goalscorers as he swept home from the edge of the area.

Welbeck claimed his second of the night shortly after, displaying more eye-catching movement to steal ahead of his marker and convert Cleverley's right-wing centre.

And Oxlade-Chamberlain completed the rout, notching his first goal in an England shirt as he latched on to a loose ball in the area and curled into the top corner.