Mike Napoli's sensational home run helped the Boston Red Sox to within one win of the World Series after they edged out the Detroit Tigers 4-3 in game five.

Napoli's homer in the second inning off Anibal Sanchez came as part of a three-run second-inning for the Red Sox, who are now 3-2 ahead in the best-of-seven American League Championship Series.

Thirty-one-year-old Napoli had also launched a huge homer in the third game of the series but his latest effort helped Boston, who had led only four of 36 innings in the first four games, take charge from the off.

It was also a decent day for Jon Lester, who allowed just two runs and seven hits in 5 1-3 innings as Boston held on despite letting a 4-0 lead after the third inning slip.

The Red Sox will return to Fenway Park hoping to complete victory on Saturday.