Battaglin fought back onto the wheel of Cataldo and fellow escapee Jarlinson Pantano (Colombia) near the summit of the final climb of the day before rounding his tiring opponents inside the last hundred metres.
It was a second win in as many days for Battaglin's Bardiani team following Friday's victory for team-mate Marco Canola - and 24-year-old Battaglin's second career scalp on the Giro following a win in last year's race.
Pink jersey Rigoberto Uran (Omega Pharma-Quick Step) was subject to relentless attacks by his rivals on the last of four climbs, the Colombian losing valuable seconds to all his direct opponents.
An exhausted Uran, 27, saw his lead over Australian veteran Cadel Evans (BMC) slashed to 32 seconds ahead of Sunday's key stage to Plan di Montecampione.
The gruelling 164km stage in the Alps featured four tough climbs including a first-time ascent of Alpe Noveis and the final trudge to Oropa, site of the late Marco Pantani's celebrated win in the 1999 Giro.
With the peloton controlled by the Omega Pharma-Quick Step team of race leader Uran as a group of 21 riders rode a maximum of ten and a half minutes up the road, it was not until the deciding climb when the race favourites started to jostle for positions.
Italian pocket rocket Domenico Pozzovivo (Ag2R-La Mondiale) made the first move and was covered by Colombia's Nairo Quintana (Movistar). Uran struggled to keep pace alongside Evans, while the impressive Dutch youngster Wilco Kelderman (Belkin) rode off in pursuit.
Quintana finished the strongest of all the race favourites, crossing the line 2:38 down on the stage winner Battaglin after distancing Pozzovivo on the closing straight.
Uran conceded 25 seconds to Quintana, 20 seconds to Pozzovivo, 18 seconds to Kelderman and five seconds to Evans, who fought back to finish strongly after an earlier wobble.
Poland's Rafal Majka and Italy's Fabio Aru both finished ahead of Uran on a day the Colombian would prefer to forget. He leads Evans by 32 seconds and Majka by 1:35 on GC, with Pozzovivo now at 2:11 in fourth and Kelderman at 2:33 in fifth. Having seemingly recovered from illness and injury, Quintana reduced his deficit to 3:04 in sixth place.
"I'm delighted with the win today," Battaglin said after his dramatic recovery was sealed in the best possible way. "I was away since the first kilometre. There were plenty of men ahead on the final climb but I managed to fight back."
Cataldo - looking to give Sky a belated breakthrough in an otherwise torrid Giro - shook his fist in disappointment after being pipped for the victory at the death.
Pantano crossed the line for third place seven seconds in arrears and ten seconds ahead of Jan Polanc (Lampre-Merida). Ireland's Nicolas Roche (Tinkoff-Saxo) took fifth place after being pegged back following an earlier solo attack on the penultimate climb of the day, the Cat.2 rise of Bielmonte.
TWENTY-ONE-MAN GROUP: Valerio Agnoli (Astana), Axel Domont (Ag2R-La Mondiale), Marco Frapporti and Emanuele Sella (Androni Venezuela), Enrico Battaglin (Bardiani CSF), Martijn Keizer (Belkin), Manuel Quinziato (BMC), Paolo Longo Borghini (Cannondale), Jarlinson Pantano (Colombia), Mattia Cattaneo and Jan Polanc (Lampre-Merida), Tim Wellens (Lotto Belisol), Julien Vermote (Omega Pharma-Quick Step), Ivan Santaromita (Orica-GreenEdge), Albert Timmer (Giant-Shimano), Perrig Quemeneur (Europcar), Dario Cataldo and Boasson Hagen (Sky), Nicolas Roche (Tinkoff-Saxo), Danilo Hondo (Trek Factory Racing) and Yonathan Monsalve (Neri Sottoli) attacked from the outset.
The group splintered on the Cat.2 climb of Bielmonte after Roche attacked from distance. The Irishman was caught on the long 30km descent before Quinziato and Timmer broke clear. An untimely mechanical did for Quinziato's chances while Timmer rode solo until being caught by Pantano and Cataldo with 3km remaining.
BIG WINNER OF THE DAY: Besides Battaglin, who came seemingly from nowhere to post his seconds career win on the Giro, Pierre Rolland (Europcar) rode into the top ten after attacking on the penultimate climb of the day. The Frenchman was joined by Canada's Ryder Hesjedal (Garmin-Sharp) to form a select chasing group, with the 2012 winner crossing the finish 2:20 down on Battaglin and a couple of seconds ahead of Rolland.
BIG LOSERS OF THE DAY: Sky's Kosta Siutsou was forced out of the race after a crash while illness waylaid Dutch stage winner Pieter Weening (Orica-GreenEdge). But Rigoberto Uran (Omega Pharma-QuickStep) won't be feeling too chipper after a tricky opening day in the mountains.
KEY MOMENT: The final kilometre had it all. What looked to be a two-way fight between Cataldo and Pantano suddenly became a four-way battle as both Polanc and Timmer returned. Then, from nowhere, Battaglin battled back - and with Cataldo crawling towards the finish line, the Italian had enough vim to zip by for the win.
TALKING POINT: Was Uran merely suffering from fatigue from his immense effort during the ITT or does the Colombian not have the climbing legs to hold on to the maglia rosa once the going gets tough?
COMING UP: The second of two Marco Pantani-themed Alpine stages concludes with the tricky Plan di Montecampione climb, which comes over 205km into the long 225km stage. Expect more fireworks.
Stage 14 result
1. Enrico Battaglin (Italy / Bardiani Valvole) 4:34:41"
2. Dario Cataldo (Italy / Team Sky) ST
3. Jarlinson Pantano (Colombia / Colombia) +7"
4. Jan Polanc (Slovenia / Lampre) +17"
5. Nicolas Roche (Ireland / Tinkoff - Saxo) +22"
6. Albert Timmer (Netherlands / Giant) +26"
7. Emanuele Sella (Italy / Androni Giocattoli) +28"
8. Mattia Cattaneo (Italy / Lampre) +33"
9. Tim Wellens (Belgium / Lotto) +39"
10. Ivan Santaromita (Italy / Orica) +54"
1. Rigoberto Uran (Colombia / Omega Pharma - Quick-Step) 57:52:51"
2. Cadel Evans (Australia / BMC Racing) +32"
3. Rafal Majka (Poland / Tinkoff - Saxo) +1:35"
4. Domenico Pozzovivo (Italy / AG2R) +2:11"
5. Wilco Kelderman (Netherlands / Belkin) +2:33"
6. Nairo Quintana (Colombia / Movistar) +3:04"
7. Fabio Aru (Italy / Astana) +3:16"
8. Wout Poels (Netherlands / Omega Pharma - Quick-Step) +4:01"
9. Pierre Rolland (France / Europcar) +5:07"
10. Robert Kiserlovski (Croatia / Trek) +5:13"
- Sports & Recreation
- Rigoberto Uran
- Jarlinson Pantano
- Cadel Evans
- Domenico Pozzovivo
- Nicolas Roche
- Enrico Battaglin
- Marco Pantani