The full-back smashed home a 35-yarder against Charlton last month but if anything topped that strike with the opener against Pompey at Stevenage. Picking the ball up in his own half, 'Steo' left a couple of midfielders in his wake, played a one-two with Andy Reid, skipped around Guatelli in the Pompey goal and slid home from a tight angle.
Capping a great night for the Club - and a 12th win in the last 13 games for Clive Allen's men - Reid marked his return to action after injury with the clinching goal in the final minute while Dean Marney and Hossam Ghaly both played 60 minutes.
It was Ghaly's first action in a Spurs shirt after a groin injury and Marney's first start on his comeback trail after rupturing his Achilles back in October.
We dominated from start to finish at Broadhall Way but only had Kelly's goal to show when we survived a huge scare with 12 minutes left. After losing possession in midfield, Pompey worked the ball to Horsted down the left flank and the winger cut inside and aimed a curler beyond Robert Burch - thankfully it came back off the junction of post and crossbar.
Charlie Daniels helped set the tone for the performance with his raids from left-back in the first half but a number of decent positions came to nothing.
Kelly's goal lifted any pressure after 21 minutes as the game followed the same pattern - Reid and Jackson pulling the strings with Ghaly regularly involved and rarely putting a pass astray. Our defence, including Tom Huddlestone this time around, was barely tested.
Guatelli produced a fine save to deny Reid and Marney might have done better after taking Reid's raking pass in his stride only to shoot wide.
We were straight into our stride in the second half and Ghaly went close to marking his debut with a goal when he whistled a header just wide. There was also a first serious scare at the other end as Mbesuma almost cashed in on a moment's defensive hesitancy only to poke the ball wide.
Ghaly and Marney departed on the hour but we had able replacements in Jamie Davis and Jacques Maghoma - Davis' pace down the right flank caught the eye and he made a positive impact, creating four chances inside 10 minutes with Maghoma forcing the save of the match from Guatelli after 64 minutes and Jackson lashing inches wide.
There was a growing feeling that it might turn into 'one of those nights' as the second goal eluded us and Horsted's fine effort onto the woodwork did little to calm the late nerves.
However, we remained relentless going forward and carved out another four chances in the final 10 minutes - Davis fired over, Jackson just wide and Reid curled over before Reid found himself one-on-one with Guatelli and there was only going to be one outcome.
GUIDE TO THE ACTION
3mins: Early chance for Jackson as Reid dinked in cross from byline, Jackson bombing into box but smashed volley over the stand.
5mins: Barcham inches away from Daniels' fine cross from the left.
10mins: Another snappy passing move as Reid got to the byline again, Jackson again darting into box but Guatelli got to it first.
21mins: GOAL. Superb effort from Kelly. Picked ball up in his own half, dribbled past about three players, played it into Reid and then continued run, Reid produced perfect pass and Kelly steadied himself, skipped around Guatelli and slid the ball home. 1-0.
27mins: Barcham worked an opening in the box but fired high and wide.
33mins: Reid played one-two with Barcham and through on goal but Guatelli made fine save, Barcham onto the loose ball but follow up blocked and cleared.
35mins: Pompey broke from our corner, McClorry-Cuthbertson opted to strike from 25 yards, decent effort tipped wide at full stretch by Burch.
40mins: Reid spotted Marney's run off the right touchline in behind the full-back and picked him out with 50-yard pass, Marney's control took him into the box but he dragged shot wide.
Half-time: Spurs 1, Portsmouth 0
46mins: Reid fizzed shot just wide from 20 yards.
49mins: Patient build up involving Marney and Kelly ended with Ghaly thumping a header just wide from Kelly's cross.
51mins: Pompey's best chance to date, Songo'o's deflected shot between Burch, defenders and Mbesuma, Mbesuma got their first but prodded wide of target.
60mins: SUBS. Marney and Ghaly off after hour shifts, replaced by Davis and Maghoma.
61mins: Reid 25-yard free-kick straight at Guatelli.
64mins: SAVE. Subs combine as Davis left Hartman standing and fired low cross in that created havoc, Maghoma eventually onto it and poked at goal from six yards, Guatelli somehow flicked wide with feet.
70mins: Decent strike from Davis taken cleanly by Guatelli.
72mins: Davis in behind full-back again, drove across goal but no-one on end of it.
75mins: Davis and Maghoma refused to let Mbesuma clear the ball tight on his own touchline, won it, Davis squared for Jackson to thrash just wide.
78mins: WOODWORK. Real scare as we lost possession in midfield, Pompey moved ball wide to Horsted who curled effort onto junction of post and crossbar from the edge of the area.
80mins: Another great chance as Davis exchanged passes with Reid over halfway and raced onto return, through on goal, got under shot and ballooned over.
81mins: Jackson shot deflected inches wide.
85mins: Reid curled a yard over from Maghoma's lay off.
89mins: GOAL. Reid broke through on goal and was never going to miss - rolled ball into corner as Guatelli advanced. 2-0.
Full-time: Spurs 2, Portsmouth 0
Spurs: Burch, Kelly, Daniels, Lewis, Huddlestone, Bunjevcevic, Marney (Davis, 60), Ghaly (Maghoma, 60), Barcham, Jackson, Reid. Subs: Martin, Forecast, Hamed.
Portsmouth: Guatelli, Eyles, Hartman, Fordyce (Roberts, 46), Day, Pearce, McGlorry-Cuthbertson, Songo'o, Mbesuma (Rogers, 88) , Swayne (Torres, 65), Horsted. Subs: Jordan, Bell.
Stephen Kelly scored another goal to remember as our reserves moved a step closer to the title by beating Portsmouth 2-0 on Monday night.