The striker finished from a tight angle five minutes before the end of the first half to claim his 11th goal of the season - exactly the total he hit in two seasons at Tynecastle before leaving the administration-hit club in the summer.
The last time Motherwell sealed a sixth consecutive win in Scotland's top division they inflicted Celtic's record defeat, an 8-0 win in the 1936-37 season, and they created enough chances to put this game out of sight before half-time.
But Hearts rallied against the odds in the final half hour to give Motherwell goalkeeper Gunnar Nielsen some uncomfortable moments, and they were applauded off the park by the home crowd despite falling 20 points adrift following Ross County's draw with Partick Thistle.
Partick were denied their first Scottish Premiership home victory of the season as Ross County debutant Filip Kiss sealed a 3-3 draw with an impressive double.
The on-loan Cardiff midfielder put the Staggies in front at Firhill against the run of play after caressing a 23rd-minute opener past Scott Fox in the Thistle goal.
But the Maryhill men responded in style as a double from new striker Lyle Taylor and Stevie Lawless' close-range effort early in the second half looked to have put them on course for their first league victory in Glasgow since beating Morton last April.
However, County left-back Ben Gordon immediately pulled one back before Kiss capitalised on Jags' jitters to slide home the equaliser with a quarter of an hour left.
County had to play the last six minutes with 10 men, though, after substitute Stuart Kettlewell was shown a straight red less then a minute after coming on.
The draw means Derek Adams' 11th-placed Highlanders remain just a point behind Partick as they both battle to avoid an end-of-season play-off survival fight.
Second-half goals from Murray Davidson and Stevie May gave St Johnstone a deserved 2-0 Scottish Premiership win over a lifeless St Mirren at McDiarmid Park.
The home side dominated the first half, with top-scorer May and skipper Dave Mackay both hitting the woodwork, but they eventually forged ahead in the 70th minute when midfielder Davidson headed in from close range following a David Wotherspoon corner.
May made sure of the points when he curled the ball in from 20 yards three minutes later, but in the end it turned out to be as comfortable a victory as Tommy Wright's side would have had all season.
- Sports & Recreation
- Partick Thistle