Crusaders ended Linfield's unbeaten start to the Premiership season and replaced the champions in second place with a 2-1 win at Seaview.
The victory came courtesy of two superb first-half goals with Jordan Forsythe hitting the top corner before Paul Heatley's dipping volley from 20 yards.
Linfield improved after the break and Mark Stafford tapped in on 71 minutes to set up a tense finale.
Crusaders held on and move above the Blues on goal difference.
Linfield had won all five league games without conceding a goal before the showdown between last season's top two.
It was a tight, frenetic start but the Crues seized control after Forsythe rifled across goal and beyond keeper Roy Carroll after 24 minutes.
Heatley made it 2-0 seven minutes later with another clinical finish, connecting perfectly to bend the ball over Carroll and into the net.
Jordan Owens and Rodney Brown both sent efforts over as the Crues ended the first half firmly on top.
The momentum switched on the restart with Linfield beginning to boss possession but failing to carve out clear-cut chances until Stafford's goal.
Aaron Burns delivered in a low cross and the defender slotted home from a yard out.
The goal sparked the Crues into life and they kept the Blues at bay while also threatening at the other end, with two deflected Heatley shots flying just off-target.
The result leaves both teams trailing pacesetters Coleraine by three points.
"We came in at half-time after what was probably our best display in a long time," said Crusaders manager Stephen Baxter.
"Linfield came back, the momentum changed and we were under a bit of pressure.
"We had to dig it out in the last 10 minutes and we did it well. It was a marvellous game of football but it's only three points."