The Federation fleet engages the Borg cube at Sector 001
The Borg cube is destroyed, but a sphere escapes
A second major Borg incursion into Federation space began shortly before stardate 50893, when the colony on Ivor Prime was destroyed. Nearby Deep Space Five detected the attack, and long-range sensors detected a single Borg vessel. Vice Admiral Hayes was immediately informed. Admiral Hayes also prevent the USS Enterprise, NCC-1701-E, from engaging in the battle stating it would introduce an "unstable element to a critical situation." The Enterprise would be forced to monitor the Romulan Neutral Zone while the Federation fleet engaged the Borg in the Typhon sector.
The conflict was broadcast on Starfleet frequency 1486 and was monitored by the Enterprise. Things did not turn out well for Starfleet in the Typhon sector. The defensive perimeter was quickly broken with numerous ships lost. The cube continued with diversion to Sector 001. The surviving ships, including the USS Defiant and the USS Bozeman, assaulted the cube all the way to the Sol system. Realizing the battle was not progressing well, Captain Jean-Luc Picard ordered the Enterprise-E into the battle in violation of his orders.
By the time the Enterprise arrived in Earth orbit, a large portion of the fleet had been lost, including Admiral Hayes' flagship. The cube itself had sustained heavy damage to its outer hull and its power grid was fluctuating. Lt. Cmdr. Worf, in command of the heavily damaged USS Defiant, ordered the ship to ram the cube. Just before the order could be given, the Enterprise-E engaged the cube and transported the Defiant crew aboard.
Captain Picard took command of the fleet and using his intimate knowledge of the Borg ordered all weapons to be targeted on a seemingly non-critical point on the cube. The resulting barrage destroyed the cube, but not before a Borg sphere was launched from its interior. The sphere made a dash for Earth with the Enterprise quickly pursuing.
The Borg Sphere then opened a temporal vortex and escaped to 2063 to attempt to disrupt First Contact. The Enterprise-E followed.
Starfleet's losses in the battle were at least comparable to the Battle at Wolf 359. The result of this battle left Starfleet stretched thin throughout the quadrant.