Hibs did not have it all their own way as Ben Williams twice made sharp saves, either side of Griffiths hitting the post, before a sumptuous strike from Kenny McLean put Saints ahead after 32 minutes.
Griffiths netted the equaliser after 37 minutes, scored his second after 65 minutes and Jim Goodwin was sent off for two bookable offences two minutes later as a fourth home win took Hibs top.
Kilmarnock goalkeeper Cameron Bell spoiled a fine performance by being sent off as Inverness emerged with a 2-1 victory following a breathless encounter at Rugby Park.
The Scotland cap saved a penalty from Graeme Shinnie just before half-time when the visitors were leading through Andrew Shinnie's 22nd-minute strike.
Killie midfielder Liam Kelly levelled in the 56th minute with a wonderful drive from distance but when the impressive Bell saw red for a foul on last man Ross Draper, it allowed Billy McKay to slam the penalty past substitute keeper Kyle Letheren.
Ross County held on to beat Aberdeen 2-1 at Dingwall and register their first victory over the Dons in the Clydesdale Bank Premier League.
A Mark Reynolds own goal from a Richard Brittain free-kick gave County the lead 10 minutes from the break and a superb strike from Steven Ross early in the second half doubled the home side's advantage.
The Dons got one back when Niall McGinn knocked in his sixth goal in consecutive league games to break a 20-year record for the club with 14 minutes remaining. But despite constant pressure from the visitors County held out for all three points.
Jamie Murphy ended Motherwell's barren spell as Stuart McCall's team returned to winning ways with an emphatic 3-1 victory over St Johnstone at McDiarmid Park.
Motherwell had gone four matches without a goal but it took less then 40 seconds for Murphy to find the net and he doubled the advantage with a solo effort before half-time.
Nicky Law added a third in the 73rd minute and the game was well and truly over by the time David Robertson netted for the hosts, who suffered their first Clydesdale Bank Premier League defeat since August.
Dundee finally ended their wait for a home win in the Clydesdale Bank Premier League with a 1-0 victory against Hearts.
Matt Lockwood's 20th-minute free-kick was enough to separate the sides as Dundee got all three points on their own turf at the sixth time of asking.