“The Simpsons” has provided countless classic moments over the years, but few are better than Lisa rejecting Ralph Wiggum on video and Bart pausing to note, “You can actually pinpoint the second when his heart rips in half.” Red Sox fans can only hope the uninspired stretch that has seen them drop from first to third in the AL East — and included yesterday’s 12-4 blowout loss to the Toronto Blue Jays — proves less traumatic. But like Ralph’s broken heart, there’s video evidence of the moment this all started. It was the last day of April in Toronto, and the Red Sox had just overcome deficits of 4-0 and 6-4 to take an improbable 7-6 lead on David Ortiz’ three-run double in the top of the seventh. The Sox needed only seven outs to improve baseball’s best record to 19-8 and extend their winning streak to six games. Instead, Junichi Tazawa walked Jose Bautista with two outs in the seventh and served up a two-run homer to Edwin Encarnacion to propel the Jays to a 9-7 victory. Though the Sox rebounded to win the next two, that game revealed fissures — inconsistent starting pitching, the inability to protect a late lead, struggles with runners in scoring position — that have since cracked wide open in May, particularly during this 2-8 stretch. Yesterday’s pummeling saw the Blue Jays slam five homers, the Red Sox go 0-for-8 with runners in scoring position and the rest not really matter. “They don’t hand out trophies in April or May, June or July or August,” said starter and loser Ryan Dempster (5 innings, seven hits, six earned runs). “You’ve got to keep grinding away for the whole year. The guys in here work extremely hard, and we’re going to continue to do that.”