The away goals rule can result in the "lead" of the two-legged tie swinging back and forth. For instance, in the 2004–05 UEFA Champions League round of 16 between Barcelona and Chelsea, Barcelona was ahead on aggregate after a 2–1 win in the first leg at home. During the second leg held in London, Chelsea first scored three straight goals to take the lead on aggregate (4–2), but Barcelona responded with two goals to level the aggregate score at 4–4 while taking the lead on away goals (2–1). Chelsea scored again, though, to advance on aggregate, 5–4. In the 2018-19 UEFA Champions League semi-finals between Tottenham Hotspur F.C. and AFC Ajax, Ajax led the tie from the 15th minute of the first leg (in a 1–0 away victory in London) until the 95th minute of the second leg (at that point still up 3–2 on aggregate), when Tottenham's Lucas Moura completed a hat-trick in Amsterdam that leveled the aggregate score at 3–3 while eliminating Ajax on away goals 3–1.